"Place" sounds very strange there. Presumably she was diving into a pool, lake, sea, ocean, swimming pool or something else containing deep water, or at least she thought it was deep water. I would specify what she was jumping into.
She jumped into the sea but it was shallower than she realised and she broke her leg.
Note that if she dived, it's unlikely that she would have broken her leg. If you dive in, it means you went in headfirst. If you did that into very shallow water, you would break your neck or at least fracture your skull.
Student or Learner