Just what I came in here to suggest—although many of the characters aren’t the most likeable. (Unless you like self-righteous wannabee hippies…it was made in 1971.)
I thought Brainstorm was pretty cool when it came out, although there’s some nudity and brief sex.
I love Twister - lots of good quotable lines, and yes there’s (some) science in there. But mostly flying cows.
Other oldies:
“Reuter’s” is more telecomm innovation than science, but it’s the only flick I know where Carl Friedrich Gauss appears.
The Mythbusters are not scientists, but they can approach their subjects very systematically. And they blow stuff up!
I’ll add my seconds for BRIDE OF FRANKENSTEIN, just for the great Ernest Thesiger as Doctor Pretorius. Heck, might as well throw in METROPOLIS because of Rotwang.
Little tho to do with science, I’ll admit.
And I will seriously endorse YOUNG EINSTEIN, because while it’s total buffoonery, all the jokes work only if you actually know anything about the scientists involved.
Speaking of Einstein, I.Q. with Walter Matthau, Tim Robbins & Meg Ryan.
The new JOURNEY TO THE CENTER OF THE EARTH, because Brendan Frasier shows his nephew how knowing stuff is necessary to survive on their adventures.
Also, the is THE SECRET OF NIKOLA TESLA and THE GENIUS WHO LIT THE WORLD, neither of which I’ve seen, but still, they’re about Tesla!
These have been mentioned here, but I’d like to expand a bit (as opposed to just throwing out titles).
“The Andromeda Strain” is a great example of approaching an unknown from a number of different disciplines. I think this is one of the best examples of task assignment and utilizing not only the specialized knowledge each scientist brings to the problem, but also how their collective knowledge leads to answers.
Both “Jurassic Park” and “Fat Man and Little Boy” are good examples of “just because we can do it, should we ?” Though not as much in “Jurassic”, at some point the “should we ?” (or “should we have ?”) question comes up, and the implications of their work/discoveries are pondered. This may be a bit heavy for a 7 year old, but I think an important lesson.
Both movies are also good examples of messing with “unknowns”, and the dangers possible.
Until it becomes an action movie, “Jurassic Park” has some decent science in Laura Dern’s character trying to figure out why the triceratops is ill. It also shows you need to get past “icky” to be a scientist. Sam Neill’s character also displays some good “inferred” knowledge given all he’s ever had to work with were fossils up to visiting the park. That is, there is a lot to be learned without having to observe a behavior directly.
Whatever you think of “Contact”, I think this movie depicts (along with “Andromeda Strain”) the most realistic first contact we may encounter with extra-terrestials. I doubt they would understand and feedback location coordinates in lat./long. as in “Close Encounters”. Nor would their first contact come in the form of an attack, as is depicted in so many movies. The point being, as profound as first contact will be, it may not be all that “dramatic”.
Monkey Business, with Cary Grant and Ginger Rogers, while totally in fantasy-science land, has plenty of “scientist working in the lab while wearing white coats” stuff. Also funny antics by a chimp, which will probably amuse her.
Of course, if you watch it too, you will be less than amused by the antics of Cary and Ginger as they try to act like bratty teenagers and children.
One of the best things I’ve seen along these lines isn’t a movie, but a 2 part miniseries. Longitude documented the story behind the greatest problem of the 18th century, determining longitude at sea. It was an adaptation of Dava Sobel’s excellent book of the same title.
I love you guys. 
It’s threads like this that make the $7.00 or so easily worth it.
Keep 'em coming!
The Andromeda Strain (TV Mini Series 2008) - IMDb Andromeda has been remade. It is not as good but still interesting.
Pi (1998) - IMDb This might qualify. I second Cuckoos Egg.
Triumph of the Nerds - Wikipedia This one is about the home computer invention and growth and change.
Them! The female scientist’s line “I don’t have time, Bob, to give you a quick course in insect pathology” has become a running joke at our house.
Phil beat me to Dr. Ehrlich, but there’s always:
Madame Curie
Creator gives us Peter O’Toole and David Ogden Stiers as cutting-edge biologists (with Vincent Spano as a grad student_
Does Forbidden Planet with Edward Morbius as a Philologist (and Engineer) count?:
Master and Commander Master and Commander: The Far Side of the World (2003) - IMDb
If she likes animal research there’s also Projext X with Matthew Broderick and Helen Hunt. It’s a bit silly but I enjoy it every time I watch it.
It’s already been mentioned, but get her started on Real Genius early. It’s sure to become one of her favorite films. There are some lines that might go over her head (“can you hammer a six inch spike through a board with your penis?”) but it’s your call if you want to wait a few years to explain that.
Well, except that it’s one of my lifetime top 25 favorite movies: the subtext about the thin veneer between civilization and chaos is pretty disturbing, if you let it be. This movie needs to be remade by David Cronenberg, updated and matured like he did with The Fly.
It’s off topic, but the scientist I most want to see a film bio of is Glenn Hammond Curtiss. The man had an amazing life and is the true father of American aviation. Before he got into airplanes, he built a 8 cylinder motorcycle and set a land speed record of 137 mph - in 1903! He was basically inventing the modern airplane while the Wrights were suing people. This bit from Wikipedia would make an amazing scene in a film:
Flew the length of Manhattan and circled the Statue of Liberty! I want to see that scene in a film! The only problem with making this film is that it would show the sainted Wright Brothers were actually litigious dicks.
I’d like to seed a biography of Thomas Midgley. He was a typical scientist with very good intentions. He had no way of knowing that every one of his inventions was an environmental catastrophy. Even so, a guy with that kind of creative genius has got to have an interesting story. Even better that he can be looked at as so evil, all the while he was actually a pretty normal bright dude with what anybody at the time would have thought as great inventions. The last one which actually killed him.
Life Story is about Watson and Crick racing to discover the structure of DNA.
Warning: Jeff Goldblum!