Helen Merrick has started a list of female scientist characters in fiction, especially in science fiction.
It's part of a research project on women, science, and fiction; but it's also a neat resource in its own right.
She has about eighty characters listed so far, by about 65 authors; I'm sure there are plenty more. If you have suggestions, use her suggest a character web form.
Note: I have no connection to this project. You're welcome to mention such characters in comments on this entry if you like, but Dr. Merrick won't see them; if you want them added to the list, you need to go use that suggest form.