I am 5'0" and I ride a 47cm Trek 1500 WSD. The 43cm bike was too small for me, but I have long limbs for my size (oddly enough), and needed to be upright and stretched out. Anyway, a 43cm Trek 1500 might be great for your friend. I paid $1000 for my 1500 and she may be able to find an older model somewhere or find a sale. The 1500 has 105 parts with an Ultegra rear der. It's a nice bike. I had a 1000 for a while and it wasn't a bad bike at all. There's not a lot of difference between the feel of Tiagra and Sora in my opinion. I certainly noticed a difference moving up to 105 though. I have no problem with the 650c wheels. I can zip up hills like there's no tomorrow. Personally, when I ride bikes with 700c wheels, even if the frame is small, I feel like I'm driving a bus. hahaha. The 650c makes me feel like I have more control. Just my 2 cents.