...when ds pushes her back down every single time she's managed to pull herself up? He's been fairly gentle/disinterested in her so far but now she's crawling faster and trying to stand we're caught in a cycle of she stands up, he pushes her down, I tell him off, repeat to fade.
I suspect that the constant "be gentle, don't push dd, leave her alone" nagging and sitting on the thinking spot only makes him want to shove her more but not really sure how else to deal with it. He's 3 in a few weeks, she's 11 months.