my wife is about the same size and when she wanted to try a road bike, I bought her a bike from Bikesdirect. It was 50cm unisex with the same Sora group for $400 new. What we found was she "needed" a women specific saddle. Other than than the geometry worked for her fine. What didn't work where the sti levers. She probably has slightly smaller hands for a woman her size but she could not confidentially stop the bike braking from the hoods. I tried shims, women specific drop bars to get the levers as close as possible and adjusting brake pull but she was literally never able to stop the bike in a reasonable distance from the hoods. She was also not comfortable riding in the drops (and thumb button was a big part of that). In the end I had to convert that bike back to flat bars for her to be able to ride it. Most of my story may not be useful, but thought I'd share