My fiancé is 5'4" so bought her a 15" myka HT thinking that she'll fit fine after but after two ride I sold the bike because she ended up with crazy back pain funny part is sometimes she rides my med sized stumpjumper and she fits much better I gues because stumpy has more upright set up so I just ordered her the small myka FSR it'll be here Tuesday I'll take her to the bike shop to make sure she fits properly before I take the bike check back with me wed morning.
By the way myka HT and the hardrock frames are not the same, top tube on hardrock curves up and myka curves down for more clearence also seat is much closer to the handle bar.