AIBU to not want a relative to take dds aged 8 and 10 ice skating, and want to supervise them myself when they skate?
I would take them myself and have done so a couple of times, but think that its actually quite a dangerous activity in terms of possibility of injury occurring.
Partly this is to do with this particular relative not having dc and not being that tuned in to the amount of support my younger child might need to help her negotiate an ice rink safely (i'd feel ok letting mil take them).
I am happy to go all together as on outing, but do feel anxious about relinquishing full responsibility.
AIBU / overly anxious to engineer things so that this relative doesnt take them alone?
It's not that dangerous - they will be fine. My Dds skate competitively, mostly in training sessions nowadays but have done hundreds and hundreds of public sessions in the past and I've sat and witnessed many more.
It is quite common for someone on the ice to have a fall and for the marshalls to take them off and that makes it look all much more dramatic and dangerous than it is. But that is one person out of hundreds and even then, for that to be a serious injury is very, very rare. Most of the time someone gives themselves a bit of a shock by falling or bumps something. The chances of your DDs being one of even those are very slight indeed.
Let them go and try to relax. The marshalls are very well trained and keep a good eye out for anything which might cause danger to anyone on the ice. So even if the people taking them are not very responsible, it'll be fine.