Scared skydiver’s mom doesn’t get to call shots
You don’t get to tell other adults how to live their lives. You don’t even get to tell other adults how not to throw their lives out of an airplane.
Not even adults who have children, and not even if you’re the parent of the adult in question.
It is simply not your business. The showiness of the risk involved with your daughter’s hobby of choice does not change this fundamental truth.
You don’t have to like this, either, or think it’s smart, or responsible, or even moral. All that’s required is to recognize adult autonomy is a complete answer unto itself. Unless you want your daughter up in your business and bills and health choices and hobby selections, you must accept there’s no place for you in hers.
You can, however, tell her you’re scared, because that’s about you.
You can tell her you’re disappointed in her decision to keep adding this risk to her life knowing it could traumatize her kids, since that’s your opinion and therefore about you. I would caution against this, though, as a poor use of your emotional capital: Given that she’s (presumably) going to ignore you and skydive anyway, voicing your opinion would strain your relationship with her for zero practical gain.
You can also tell her you would like to talk about any arrangements she has made for the children in the event of her death — specifically whether these plans involve you in any way. That your business, perhaps (over)due to be discussed.
Dear Carolyn: Is it morally justified, on principle, for those who invite adults to weddings to exclude children, unbeknownst to their solid character and responsible actions? My child is an angel and would be a great part of any wedding procession.
Not inviting your child to a wedding is immoral. You basically just said that.
To answer the question you asked, yes, it is morally justified for hosts to throw a party just for adults.
To answer the question you didn’t ask, no, your angel will not remain angelic if you transfer to her any of the sense of entitlement you just put on display.
It’s fine to be besotted with your child. It is not fine to believe you can hold the rest of the world accountable for not being as besotted with your child as you think it should be. Please, please. Just stop.