Thanks guys!
She is a good friend's niece from out of town. She is an ex-gymnast and competitive cheerleader, and comes to visit at least once a year. This isn't the first time I saw them taking jump pics at sunset. I didn't want to impose so I wandered over to get some pics from afar of them taking pics. My friend saw me and asked her to do some more jumps for me and she happily obliged.
It's hard to improve a sunset on the beach but she made it look easy.