MIL not sticking to any routine

My MIL is now looking after my LO a few days a week now I’m back at work and literally does not stick to a single part of her routine and it’s driving me absolutely nuts. That being said I don’t have this super strict schedule that I try and keep my LO in but I have a basic routine of naps, lengths of wake windows etc. my LO hasn’t ever been a great sleeper and not getting decent naps in the day really seems to impact her night sleep so it’s something I really prioritise for her. My MIL is allowing her to stay awake for hours on end (she’s 9 months) wakes for the day around 6.30am most days and usually would have her first nap around 9.30/10am. Today my MIL didn’t have her nap until 2pm that’s a 7 and a half hour wake window! By the time my partner picked her up at 4 o’clock she’d also not fed her any of the food that I packed for lunch and said she’d given her a biscuit and a yogurt which was full of added sugar and our LO was really cranky - this isn’t the first time a day like this has happened while she’s had her. I’m so angry and feel like she’s just totally disregarding and disrespecting me as a mother and I’m at the point of looking into nursery or a child minder instead. However, my partner said this would end up defeating the purpose of me working as we’d be spending so much on childcare and he also doesn’t want to upset his mum. We‘ve never had any issues between each other but I feel since my daughter was born she just dismisses everything I say and always says the same thing about how she’s done it all before with her own child and nieces/ nephews. So true but that was 30 odd years ago 🫠🫠