I too would be fucking fuming. If you see them again flag them up with the owners - she should not let her son on soft play if he does that. She delay With it shitly and should have talk him straight off. Your poor niece!
Oh god. YANBU to be distressed about your poor DN. YABU to call the biter a horrible child. You admit he was likely younger than 22 months, i.e. he's only a baby. Negligent parent, maybe. Horrible child definitely not.
My DD got her face really scratched and eyes gouged when she was 2. God it was awful. I'm very relaxed about these things normally. But the lady running the place said this child was always doing things like this. I mean, why take them out to softplay if you know this will happen. My friends DD was always a bit of a puncher but my friend HOVERED like a loon whenever she went out.
Well I wouldn't blame it on the little one but mum should have been carefully monitoring him knowing that he is inclined to bite. I know people don't want to helicopter but if you know your child might hurt someone than you need to be on top of it. I empathize - my son is super passive and will just sit there when older babies are trying to munch off his face. I have to hover so I do.
My DS is 16mo and a terrible biter, hair puller, hitter... It's the most mortifying thing in the world, and i DREAD taking him to groups. But i do, because it's good for him, but i don't leave his side! There's nothing worse than parents letting their children run wild, knowing what they're likely to do!
YANBU. Children who bite should be closely supervised. No way should a situation arise where they have the chance to attack another child 3 seperate times! I have every sympathy for parents who have children that bite/punch/hair pull etc (it must be hard), i would lose it fast if they are allowing their child to roam free. Awful.
I feel sorry for your DN but if my toddler or one in my care had been bitten I would have gone in the toddler area with them. Yes it SHOULD be the biters mum that does the monitoring but she obviously wasn't despite her knowing that her child was a biter.