It is also probably worth your while to run some searches here on TE regarding bikes for petite riders. You will no doubt come across a few discussions re: 700 v. 650.

I'm 5'1" with a 27" inseam. My road bike has 650c wheels. I also ride a folding bike with 20" wheels, which I find extremely comfortable, and I love that it has a low stepover. I have a bad hip, so the low stepover makes it easier to get on and off, while I am not so graceful getting on and off my other bike.