I think my sisters parenting is so extra, that whilst I believe your children should be your top priority, I think her reactions to thinks are out of proportion.
Example: we both think our children should not have to kiss/hug anyone they don’t want to. So I said to her 2 year old after a family meal out, ‘cuddle goodbye?’ Her 2 year old just stood there so I said ‘no?, Ok’ and stood up. My sister pipes in, talking to her daughter ‘we can say no auntie Kate can’t we, tell auntie Kate we can say no’. I was so embarrassed as it was in front of everyone, I said I was not pressuring for a hug. She said oh I know we’re just teaching her she can say no. I agree with the concept but she’d have learnt from the interaction with me alone she can say no.
My mum was doing my sisters 2 year olds nappy. She initially wouldn’t lie down for it and when she did my mum said ‘oh well done, good girl’ or similar. My sister said mum was overdoing it with the praise and asked her to tone it down as girls are taught to be obedient and she doesn’t want that. (Note: my mum treats my son exactly the same, lots of praise when he does as asked). She does this sort of thing with my mum a lot and my mum is feeling constantly criticised and untrusted. My sister told my about the nappy thing, expecting me to agree but I told her you can’t micromanage every interaction.
I have an isofix car seat for my son in my car and bought a cheaper one (but new and from a reputable place) for my mums car for occasional use. My son is the same age as my niece so they both fit in it. However my sister has told my mum her daughter is not to use it as it’s cheap and doesn’t rear face. She doesn’t feel it’s safe. But hasn’t bought one herself. Didn’t share cost with me when I suggested we buy one together they can both use. Has never learnt to remove her own car seat to put in my mums car.
These are a few example but I could go on. Next time she says something similar to me or tell me about something to do with my mum I feel like it’s all going to spill out.