In laws 😕

Hi mums x a bit of a vent because i don’t know what to do anymore and it’s very tiring repeating myself day after day.. my daughters father and i are not together although he helps me out a lot because i cannot drive so we see each other often. my daughter has eczema and i’m constantly doing things to help prevent her skin from itching, and flaring constantly. i don’t allow her to eat unhealthy foods to help & only use earthwise natural washing powder. this is so she’s not leaving marks on her skin or so she’s not having completely dried out skin. This has worked & it’s almost as if she doesn’t have eczema. Except everytime she’s with her father’s mother she completely takes over and does everything her way and orders us to do things for our daughter like we don’t know her. She uses softner all over her clothes and random powders that are in reach. Feeds my daughter nothing but crackers and overall acts as if her way is better. When she has 8 kids with eczema she never cared to look after. I’ve told my daughters father millions of times not to let her use whatever and do whatever but he doesn’t care because he thinks i’m just trying to ruin his relationship with his mum and family. Please help what do i do now?? nothings working and i look as if i’m the bad parent when i’m just looking out for my daughters health.