Im about 5'3 and ride a 49cm vintage road bike. So the size is probably close to right, if not just right. I think surprising her would be great, but I also think you should have her test it first lol Just to make sure...it can still be a surprise, ya know? Its a beautiful bike, and I would love to be given one of those! Lucky girlfriend you have. The price is about the same as it would be in my area.