I just read a blog about how important it is to read science stories to your daughter. I completely agree! Pull out the nonfiction alongside the fairytales!
I also feel it is equally important or more important to encourage your daughters to be curious learners. Read the books, but also get them outside to enable them to have their own experiences with the world around them. Take them on walks in the woods. Show them how much fun a museum can be. Listen to all kinds of music. Providing your daughter with all of those experiences will help them conquer anything that comes there way. Teach them to question. And also show them that there is hardly ever one right answer (except in math). Even science doesn't answer everything.
Explore books of all kinds. Read the fairytales and come up with different endings. And yes, pull out the nonfiction, but don't just read it - explore it!