A bit of background info..
I have 2 DC, I work for the NHS, OH works away for weeks at a time with no set rotation. Due to a family friendly work policy, I have a set 12.5 hour Monday night shift a week so that I can make sure I have childcare when OH is away, as he sometimes leaves with 1 days notice.
Anyway, my MIL has my children overnight while I work - this was the least disruptive option for her and my children, considering the start/finish times of my shifts. She has done this for years, and has always ignored my rules - "I was a mum first... I've done my time of listening to other people's rules... I make my own rules" etc. She always wants to be the saviour/fun adult. An example, during mealtimes, if my children don't want to eat their dinner, but I am attempting a negotiation with them, she will plonk a plate of toast down in front of them and swipe their dinner away, without even a word to me. Very annoying, I have bitten my tongue many times to save arguments. She also used to put DS to bed around 10pm at just 2years old when she had him before DD came along. She would completely ignore any routine I had, and it would make it tough the other nights when I was on my own. Fastforward a few years, he is now 4½ and in full time school, but she still puts him in bed at 9pm regardless of how many times I explain that he needs to be asleep by 7:30pm (DD goes to bed at the same time, but at least she naps in the day). He then can't catch up on his sleep for days, and is a total nightmare because he is overtired from 5pm every day, which is really tough when I'm alone for weeks at a time. I have tried, OH says he has also tried, to explain the importance of him getting an early night but she just doesn't listen, and will often roll her eyes at me. Last week, she took them out for a walk and didn't get home until 7pm, then put them in the bath, then took them back downstairs for a toast picnic on the sofa while they watched a 30 minute TV programme, before finally taking them up to bed for a story. Problem is, I need her! Without her, I will struggle with childcare for such long hours, and she knows it. But my son is suffering, and sooner or later his schooling will suffer too. But I don't know how I can do anything more, when I'm not physically in the house and I've been trying for years to get her to respect the most basic of parenting rules I ask of her. Sticking to bedtime routine - bath, story, asleep by 7:30pm, and once they're upstairs for the night, they don't go back down, is all I ask. AIBU as she's doing me a favour? Are my rules really asking too much?
If you've made it this far through my ramble, thank you!