I had to do some research to find out the answer to your question... Let's just, err, not discuss how I found this out.
「子宮がうずく」, according to the great internet at least, is an expression usually used under a sexual context meaning "to get really excited". And I mean, like.. really excited. I'll spare you the details, but it is generally used in situations like one where girls go to a bar and they see a really handsome guy, so they say that he's a ”子宮がうずく男". The nuance behind this is that regardless of whether or not they like that guy, they find him attractive, so you can kind of guess the rest.
I am really not sure why that woman said that, though. I could only find sexual contexts for that expression. There is some chance she said it tongue-in-cheek, but I really can't say. I most certainly did not find any evidence pointing towards "wanting to have a baby".
Anyway this is what I could come up with, maybe a native speaker can tell you more.