My daughter is 8 and just started jumping 80cm. I was still okay when she played around on the lower jumping. Two weeks ago she fell and I stood there and had to see her getting back on and redo that exact same jump over and over till she felt confident about the jump. It almost freaked me out.
One of the other people said to her that they would have never gotten back on and she turned around and said "Riding is not for Wimps"
At that moment I could not decide if I was proud of her or if I would rather have a Wimp as a daughter.
My mother was different to most! Her attitude to my sister and I riding was always one of laughing off injuries telling us "worse to happen before you die," or "if you can't take the heat in the kitchen, stop cooking."
I once arrived home with my face smashed in. Mum, getting oor meal ready, took one look and dissolved into fits of laughter and when she could talk said " Well you won't want vinegar on your fries!"
Only twice did she ever frighten me with her reaction. Once with a concussion when she never laughed and said "Better get you to the doctors." The other was when I had my teeth kicked out. Both times, because she didn't laugh, frightened me.
Odd thing was, after the teeth incident, I went into the other room and her mother was there. Gran immediately said "Worse things happen at sea, you don't drown riding horses!"
I knew where it came from!
It is natural for mothers to be protective, just keep those fears well hidden!
The only thing I think you can do is a mom is be comfortable she's good at the level she's at and moving up the jump sizes conservatively, and that she's on a good, reliable horse. When I was little I fell off a bunch of horses... it never seemed to be that big of a deal. Happened. Flash forward to my 30's and my first fall had me icing my back for 3 weeks. I like to think kids are a little more elastic. :)
That said, there are of course risks. But I think so long as you stay conservative on her horse and her pacing, you minimize those risks to a healthy level.