Originally Posted by Dunbar

Yes, the shoulder pain is probably from having to reach too far and a 20" is not recommended for her height. I had the same thing on my road bike before I put a shorter stem on it. For a 5'6" individual with long legs a 17.5" frame is just about perfect. I would not recommend getting the 15" frame since it could result in having an uncomfortable amount of saddle to bar drop.