No I don't get it, sorry. If we go out in the evening it is much easier to have MIL look after our kids while they are asleep in their own beds (they are too young for sleep overs).
And really, unless you have a dead body in your cupboard, who cares if she looks at your linen? (I have to admit I had a peek in my MIL's linen cupboard to see if there were any vintage sheets in there I could ask for to make stuff with)
If she folds our washing (which she always does), I thank her. I am a lazy pegger, one peg, haphazardly pegged on any part of the clothes. MIL re pegs stuff so it has more pegs and hangs `properly'. I don't care, I have more important things to think about than how stuff is pegged out or if she touched my undies when she folded them up.
Raising a kid is sooooooo much easier if you accept help from your village- even if that help is sometimes a bit meddling.