My advice? Look around on the net for Irish newspapers and such to pick up on Irish names then check the pronounciation on an “Irish baby names!” website.
I had a friend a few years ago named Roisinn - Gaelic for “Rose” from what I understand, pronounced “Roi-shinn”. I always thought her name was as lovely as she was.
“Roisin” seems to be very common around the Liverpool area, which is where I live. Because of the Irish ancestry of a lot of Liverpudlian people, you get lots of Irish names.
Suggestions:
Niamh
Aoife
Carrie
Nina
Siobhan
Iona <-- my name(!)
I also second Rowan, Morgan and Genevieve.
So the following names are absolutely verboten: Emily, Madison, Hannah, Emmas, Alexis, Ashley, Abigail, Sarah, Samantha, Olivia.
Eliminate weirdly-spelled Celtic or Gaelic names, unless you are actually from Scotland or Ireland. “Cthion,” pronounced “Maryellen,” might sound cute and trendy to you, but your daughter will curse you to your graves for giving her such a hard to spell name. Besides, weird-spelled Celtic and Gaelic names are a current fad, so her name would be dated AND hard to spell.
Then eliminate all alternate spellings of real names. If you want to name your daughter Catherine, do not spell it “Khatherirynne.” Go for the most common spelling of the name, no matter what. What matters is how it sounds; spelling it differently doesn’t make it prettier.
Eliminate all names that are either a last name (Morgan, Madison. Mackenzie) are Frankennames (Makayla, God help us all) or geography lessons (Dakota!)
Having eliminated all these bad choices, pick a known but not very common name that sounds pretty and does not rhyme with your last name. It should also not start with the same letter as your last name or the first name of your other kids.
Based on my criteria, which no sane parent in North America should ever stray from, your daughter should be named “Claire,” assuming your last name isn’t “Blair” or “Ware” and doesn’t start with a C. It’s low on the baby name charts but is a classic and instantly recognizable name. It’s feminine and beautiful, but not juvenile, so it works for both a child and an adult. Most people can spell it, it’s easy to pronounce, and it’s not trendy. Perfect choice.
I think Rickjay’s right.
Claire is wonderful, even if Judd Nelson does think it’s a “fat
girl’s name” ;).
So Olivia is becoming too popular? I love that name, along with Sophia, which is also, unfortunately, becoming way too trendy.
I agree with NO Ashley, Caitlyn, Taylor, or especially Madison.
Gee, what about Britney?
I did know a girl in college named Elizabeth, but she went by “Lizie.” (sounds like Heidi).
Always thought that had a neat ring to it.
Also just thought of Cecille and Celia, both lovely, and not too trendy right now (at least I don’t think…)
I know a Lucia, which I really like, although somehow it’s
prettier on paper than spoken, IMO.
Or-let’s see…
I’m a Sarah, but I go by Sally, which is a fairly servicable name, even if the music industry thinks it’s slutty
“lay down Sally”, “Mustang Sally (all ya wanna do is ride)”,
“sneakin Sally through the alley”, etc.
Geez!
My sister is Farrow, which I’ve always liked. Family name.
Again, though, perhaps prettier on paper than spoken. I had a friend who thought it was spelled “Pharoah”.
Yikes!
Ivy.
I wonder why it is that names seem to run in cycles like that … ? Grace appears to be the new Jennifer, based on the responses of people here on the boards. It is a beautiful name, sure, but why does it appear to resonate so strongly with so many people? Someone needs to do a research study on this!
I would second Stella, and offer Mariel, Brenna (of Celtic derivation), Chloe, and Hannah. Though I hear that last one is becoming terribly popular, too! Darn it!
Names that are of Gaelic/Irish/Celtic origin and are not too common/trendy at the moment (at least as far as I am aware):
Brenna (already mentioned, means “raven”)
Colleen
Dierdre
Erin
Fiona
Glenna
Gwendolyn (Gwen)
Kelly
Kerry
Leslie
Lorna
Lynn
Moira
Megan
Rhiannon
Shea (“Shay”)
Shannon
Sheila
Tierney
Wynne
Olivia was the 10th most popular girl’s baby name in 2002 in the United States, having been given to over 14000 babies. I would assume English-speaking Canada is not much different in terms of ranking. (I’m assuming the OP is one or the other.)
Others cited in this thread:
Ivy - 406th most popular name, 710 babies.
Claire - 95th, 3385 babies.
Sarah - 8th most popular, but that doesn’t include “Sara,” which by itself was 59th. Combined, “Sara/h” is actually the 3rd most popular girls’ name.
Celia - 647th, 389 babies.
Cecille - Not in the top thousand.
Sophia - 27th, 8613 babies.
Britney - 236th, 1336 babies, but “Brittany” is at 175th.
Grace 15th, 11912 names. Far too popular to make a good name. Plus, “Gracie” is at 157th., which really bounces Grace up to 12th.
In case you were wondering, the do-not-touch list for boys is Jacob, Michael, Joshua, Matthew. Ethan, Joseph, Andrew, Christopher, Daniel, and Nicholas. Unlike girls’ names, boy names don’t change much from year to year in terms of popularity; in 1992, the top six names were also in the top ten in 2002 and the 7-10 names were still pretty popular. By comparison, the 1992 list for girls is a bit more varied from its 2002 incarnation.
If you go back further, the girls’ name lists REALLY changes, but the same standards always top the boys’ list. “Michael” is #1 or #2 almost every year.
IMHO, the perfect boys’ name is now “Richard.” Of course, that’s my name, but it works perfectly - it’s understood but not very common anymore, masculine, has a lot of short forms and sounds good. “Patrick” is good too, as are “Charles” and “Dominic.”
Other interesting notes:
JACOB has exploded in popularity since 1990, for some reason, going from a below-20 choice to top three every year and has been #1 four years running.
JOHN has not been in the top ten for a decade now.
JENNIFER, once the undisputed, undefeated champion girls’ name of all time , has fallen to 28th.
The ridiculous MADISON has become popular only since women started having babies who were about the right age to have seen the movie “Splash!” when they were preteens/teenagers. (The name was given to the mermaid in the movie as a joke.)
MACKENZIE - God help us all - has also just happened since the Madison craze. Same with “Makayla.”
Veronique…
Hudson.
Kathrine (Kate)
Rose
Faye
Ariana (Ana)
Samantha (Sam)
Charley
I’ve always loved these combinations…
Savannah Rose
or
Delaney Grace
In doing genealogy research, I noticed it was once popular for many women to make their maiden names the middle names for one or all sons.
Martha (nee Emerson) Curington’s son would be
John Emerson Curington, so on and so forth.
I like that tradition & it passes your maiden name down.
That naming convention has helped a lot of people trace the matriarchal branches of their family tree.
People like Shannon? It was popular the year I was born, but other than those people right around my age, I don’t think I’ve met…any. I blame Shannen Doherty for people asking me how it’s spelled, though, since until 90210 came out, I never was asked the spelling. Apparently it’s also “cute” to spell it with a “y” but…ick.
Generally speaking I loathe place names, but I do have a soft spot for Paris (well, London too, but it’s a boy’s name, I think) . It ranks #464 for 2002, so I’m not in good company, apparently.
I also like Arden (not in the top 1000)
Paige (#49)
Delaney (#183)
Danielle (# 71)
Jude (#533)
And I’m frightened to know that my (dearly departed) dog’s name, Princess, is not only given to humans, but ranks #854.
Doh, no offense to your sister, but a farrow is a litter of pigs. It can also be a verb to give birth to a litter of pigs.
If her elementary school kids had had a larger vocabulary, she might have suffered terribly.
Of course, I do appreciate and long for something more unusual, since I’m one of a billion Jennifers. I wish I had been named something lyrical and romantic like Rhiannon or Aurora.
My name is a very Irish name and doesn’t begin wiith a C or M (were those the right letters?) so I declare that you can name your new daughter “Darby” 
Although I have found in my life thatit can be considered a last name so if that’s a no no I declare you don’t have to name your new daughter “Darby”
Wow… so many fine choices, and everyone seems to be so laid back about baby names. No strong opinions here. Nope. Nosirre. Not a one.
With the first two kids the choice of the name just seemed to come to me. I can’t explain it, except to say that one day, I considered the names and I thought, “Yep, that is what I will name my child.” This time around it is much more about “I can live with that name.” I’ve gone from thinking “this is the name I want” to “this is a name I can live with”. Considering she will have to live with it for the rest of her life, I’m not so sure that is a good thing.
To everyone who tells me not to pick a “top x” name, no worries. I really don’t intend to. I’ve also taken to heart the advice not to spell it in a “different” way.
I think I’m leaning towards Laura.
It is 104 on the list of 2002. It is not spelled differently. There are Lauras who are CEO’s. The association to Laura Bush isn’t necessarily a good one, but it isn’t a detraction, either. It isn’t celtic, but Erin just doesn’t feel right and Erin was the only celtic name I really liked. It doesn’t start with A or M. It doesn’t rhyme with my last name. It doesn’t match the first letter of my last name, but it will match her middle name (Lynn), unfortunately.
Laura Lynn
I eagerly await your approach, little one, whatever your name shall be. You’ll excuse me while I go feel her kick some more.
I’ve always liked the name Lydia, and I never seem to meet any!
And personally, I think there should be more Maryna’s in the world… but that’s a bias 
Oh wow-blast from the past-I’d forgotten!
Poor child. She didn’t need mean classmates; yours truly
looked it up in the dictionary and tormented her until she actually went by her middle name Jane for a few years!
I’ve never met anyone else who knew that though-is it in common usage?
We don’t know any pig farmers, although of course I suppose that we must have been just that back in England, generations ago!