My sister's asked me to help her move some stuff out of her storage unit and I'm happy to help and I will shut up and do as I'm told and i will not lose my temper and throw something at her and I will not question her even though she does things the wrong way and I will pray.
When I was helping my bro and SIL move their shit recently they did fuck all and I'm still bitter. They didn't even prepare things for moving. I rocked up to a complete mess and was expected to both organise their shit and move it.
They just stood around watching. When I was carrying their (heavy) chair from the truck, bro said "oh can you just put it in the lounge room" which was the straw that broke the camel's back. The audacity. I said fuck off. That felt good.
You're a braver person than I am. Soricide is still against the law, but soooo tempting in these circumstances. Still, its her stuff so she gets to decide.