P.M.
Doubtful it would be dysplasia, but have a doc look anyway. If it was a displasia one of her legs would be appear a little longer that the other (from the bones being misaligned. Your doc checks this every time he pulls her little legs straight with her feet together.
My son was a preemie and popped all over the place in his first six months with every joint. Eventually the ligaments tightened up and it quit, only for him to start having this intense pop from both his hips! We freaked because he was three and it was happening. So a trip to the pediatric orthopedist and an x-ray showed he just had "snapping hip" syndrome. Nothing to worry about, though she was surprised to see someone so young with it.
Bet you're little one is just fine, but go to the doc and have them check it out.