Ohhhh. I HATED that Woolies Lego! MIL gathered heaps of it & gave it to DC even after I asked her not to, as it becomes a pain to collect it all!
Anyhow I digress. My MIL was similar, with a dose of verbal abuse. DH took many years to see it, after she went too far & I threw her out of my house.
What saved me was realising I didn't respect them (MIL, FIL & SIL) & decided I didn't care what they thought or said & their behaviour wasn't my problem. I wasn't rude, but didn't engage & only saw them when absolutely necessary, didn't attempt to fit in, didn't sit while insults flew (MIL still tried to slide them in) and it was so empowering. I just didn't tolerate it anymore.
When MIL would comment on how I should do things I'd reply politely that I'll do it my way, thanks, we won't discuss this again.