bjg, you restated your opinion, you didn't justify it. Growth plate damage? Dude, growth plate damage is generally caused by contact sports. Jumping and landing on your feet causes more stress to growth plates than deadlifting. And "not a natural thing for girls to do"? Give me a break. Deadlifting isn't a natural thing for *anyone* to do. Neither is bench pressing. But getting stronger is very much a natural thing to do, and whether the method is jumping and tumbling or lifting heavy weights, it's still all about getting stronger. And who is pushing her? Read her backstory, dad took her to a powerlifting meet, and she liked it so much that *she* is the one pushing. And holy cow, she's got a half-decent coach... her deadlift form is textbook perfect.
As a kid, did a lot of people tell you you couldn't do things because 'that's not normal'? I've learned to let kids do what they want to do, and give them whatever support you can.