Some oddball ones…
The Absent Minded Professor
Weird Science
Real Genius
My Science Project
Back to the Future
Dr. Jekyll & Mr. Hyde
I love this movie too. Note that there is a bit of an adult theme in places with Watson’s (Goldblum) notorious ogling-the-girls behavior. Oh and Goldblum makes a comment about a club being men-only. “What, do you have urinals in there?” That sort of thing. 7 is a bit young, but okay for a teenager. Also called “Life Story.” But the real bad news: no DVD as far as I can tell.
Sebastian is my all time favorite computer geek type film. Lot’s of smart women codebreakers. Caution: obligatory 60s party scene. Alas, also no DVD.
It probably won’t appeal to a seven-year-old child, but the HBO original movie Something the Lord Made was very good. It was about how a white doctor and his African-American lab assistant did pioneering research on heart surgery during the mid-20th century. A good part of the story is about the racial attitudes of the time but it also gets into the research process somewhat.
Jurassic Park
I heartily second this one.
Not strictly on topic - but I do love any movie featuring a female scientist whom no-one realizes is stunningly beautiful, because she’s wearing glasses. 
In the same vein, *And the Band Played On *is a fasinating movie about the doctors who “discover” HIV/AIDS. But probably too old for your daughter.
Ghostbusters. “Back off, Man. I’m a scientist.”
Okay, actually that character is the opposite of what a research scientist should be. When first seen, he’s falsifying data. Poor excuse for a scientist.
If you can find it, Glory Enough for All, about the discovery of insulin, is very good; as an ex-research worker, I found it pretty realistic as well. However, some parts are not really suitable for a seven-year-old. Save it till she’s 12 or so, or watch it first so you can skip the dodgy bits (IIRC, almost none of them contribute anything essential to the plot; they concern Frederick Banting’s WWI experiences and relationship with his girlfriend. The exception is a brief slideshow of what diabetes actually did to children when it couldn’t be treated–unpleasant but worth knowing.)
Creator is about scientists’ work, kindasorta.
Come to think of it, I’ve never seen a big-screen biopic about Newton or Darwin or Einstein. But I have about Edison, who was no scientist; inventors are more exciting, I guess. How could you make a riveting film about the Michelson-Morley experiment?
This Island Earth
When Worlds Collide
A great film, and many of the extras in the movie are scientists.
The made-for-TV Day One deals with the same subject, but from a slightly different perspective and is worth watching along with Fatman and Little Boy.
The various Star Trek TV series and movies have been rather effective recruiting tools for the sciences.
From the Earth to the Moon deals a lot about the engineering and science that went into the Apollo programs, and IMHO, For All Mankind is pretty much the documentary about the space program. It deals with the astronauts going to the Moon, told in their own voices, but there’s a good deal of scientific data in it the film.
There was a good BBC miniseries, The Voyage of Charles Darwin. Criminey, has it been 30 years? Great miniseries, but you can’t see it, because it’s not available on video.
I’d just like to state that I have never seen a movie accurately portray real scientific research as it actuaqlly occurs. You cannot synthesize a new drug in a week. Even simple compunds can take a month to get right if it’s never been done before. It takes years to figure out how to manufacture a new compound on a large scale. In a chemistry lab, there is a lot of just sitting around and reading while you wait for your reaction to finish. Some chemists have the luxury of setting up multiple reactions at once, some don’t. Analyzing a new compound can take weeks. Actuall research is incredibly slow. The researchers that get interesting discoveries every few years have huge groups of thirty or even fifty extremely bright people working for them. The social dynamic is unavoidable. The cliques are like highschool. You work all hours of the day. Sometimes you go to the bars and come back to finish your reaction at 2 AM. Sometimes you just stay at the lab all night surfing the Dope checking every five minutes to see if its done. Sometimes the flask blows up in your face or catches fire destroying the last three months of work. Sometimes the reaction just sits there doing nothing at all.
No movie has ever really captured how research as I experienced it works. It’s too bad, because it would be a very good movie. It just would be a very different movie from what the movie industry has told you about.
The Core.
d&r
Okay, I’m back. How about…Groundhog Day, which, while not a movie about scientists, shows a good approximation of the scientific method?
How about “The KGB, The Computer And Me”? It’s a documentary/re-enactment of Clifford Stoll’s tracking down of a hacker that started with his noticing a 75 cent billing error. It’s based on his book “The Cuckoo’s Egg”. IIRC I saw it on “Nova” years ago.
Another vote for “Apollo 13” - real engineers, real adventure.
Primer is a good movie, but it might not be very interesting unless she “gets” it.
Medicine Man, not a great movie by any means, but it certainly is scientist related.
How about Dr. Ehrlich’s Magic Bullet? Made in 1940, it starred Edward G. Robinson as Paul Ehrlich, the man who discovered a cure for syphlis.
Love, Phil
While it’s not exactly all about scientists, maybe she’d enjoy Sneakers. It’s one of my favorite movies and it has a lot of realistic elements from phreaking / hacking / computer culture in it. That’s kind of sciencey, right?