I thought it was going to end...
...with the daughter losing her arm in the death roll, too. I thought she and the dad would wind up mirroring each other in that regard.
It would have been a REALLY dark ending, though, considering that would basically be the end of her competitive swimming career. She'd be devastated by that.
If they did that, you'd almost need another movie to finish the story off and show her moving past it.