Long post, sorry.
Pre-dx but pretty sure ds (3.3) has asd. One of the most challenging behaviours atm is his aggression towards dd (9mo).
Much of it is obviously simple jealousy and feeling threatened, but it has escalated intensely since she started crawling (she is incredibly determined to get to him and whatever he is playing with). He cannot stand this (his sharing skills are not great at the best of times though improving with his peers), and he will kick out at her, throw things at her (today was a piece of celery), sometimes even go to pinch her (which he sometimes asks me if he can do beforehand ).
He does want to play with her though, and there are some nice moments of chasing each other, and he does hug her but even that is sometimes rather, um, ott.
All the usual things you would hope would work on a nt child (positive reinforcement, repeated "gently", "no hitting", time out, removal etc) just do not work. It feels I am repeating myself over and over and over again, day in day out with no change. I am spending all my time just hovering over them as I cannot feel I can leave them for a second in case she really does get hurt.
Any tips please?
Btw we're going to be starting ABA soon so I guess something based on that approach would be good for consistency.