DD1 is 14 and just joined BE. She's been doing great at unaffiliated and NSEA 90s and has ambitions to move up to 100s and beyond... there's even been talk of her getting the ride on an amazing schoolmaster that has taken riders from 90 to 2*.
Now I'm scared! The jumps are massive and it's such a dangerous sport. I am a huge coward myself and I'm so afraid of her getting hurt.
So, what does a good parent do? Encourage and support her dreams regardless of personal scaredy cat feelings. Or actively discourage, try and keep her to the lower levels and hope she grows out of it 
Fwiw DD is not a gung-ho type, she is well aware of the dangers of the sport but still wishes to pursue it.