I'm liking the suggestion of Kristen Bell as Murphy.

Maybe if she was a bit older, but other then that she's perfect and got the acting skills

Sometimes a young age can say a lot about the character the same way an older one can- it says she worked very hard to get where she is now, especially when you take into account politics and sexism in the force.

And I'm no age-ist, but Murphy being referred to as "cute" kind of made me think she was younger than her 30s. I just don't associate that word with people above a certain age.