First of all, congratulations to you and your daughter, and to the little one who is being adopted into your loving family! This warms my heart.
I have a 6 month old who was extremely colicky for the first 11 weeks of his life. He cried non-stop for 6 or 8 hours a day, every day, and there was precious little we could do for him. We read several books, talked to a couple of doctors, and read everything we could find on the web. We also tried hundreds (I’m not kidding) of safe folk remedies and diet changes recommended to us by friends, family, and complete nincompoop strangers who couldn’t help themselves. None of it worked. For a little background, he is/was breast fed, had no physical ailments that the doctor could find, and slept just fine every night. He just couldn’t deal with being “on the outside.”
The things that worked best for our son were loud music (not too loud, of course, just loud enough to make it difficult to hear much else, and any type of music worked), taking him outside, walking him around and bouncing him lightly while doing the “colic hold” and making loud “shhhhh” sounds, and baths. You can find the colic hold by searching the term on Google. Strangely, placing him in a bath consistently and instantly made him a happy baby. He would resume crying the moment he emerged from the water.
If it’s true colic, the problem lies somewhere in the little one’s grey matter, and it’s just a process of trying different things until you find something that soothes her. Whatever you find might only work for a day or two, then you’ll need to figure something else out. It sounds like your little one may have reflux problems, which I personally don’t have any experience with, but I have several friends who had near miraculous results with prescription antacids. I’d definitely look into that, if you haven’t already.
As a side note, your daughter will probably be afraid to take the kid in public if it cries a lot and very loudly, since people will give her dirtly looks, assuming she’s ignoring the child’s needs. Please be cognizant of that. People can not and will not accept that a crying baby isn’t physically suffering or extremely tired, and they will judge her and give her (often ignorant) advice. Please reassure her if she gets discouraged that the child is just fine and it will pass. She’ll need to hear that regularly. I wish someone besides our doctor had reassured us; we were just made to feel like horrible parents who didn’t know how to care for our poor, helpless child. It’s a terrible thing when the people you depend on for love and support not only don’t provide it, but essentially tear you down, especially when you’ve never done less than what’s expected of you.
For us, at 11 weeks the crying stopped. Like, one day it just stopped. Now our boy is 6 months old, in the 85 percentile for weight and head circumference, and 98% for length, and he’s just about the happiest boy you’ll ever see
Good luck and God bless!