I was in a cafe with DM with my son 6 and dd 1. Its a very small cafe with 1 restroom (unisex) and if someone is in the toilet you have to wait outside the door until they come out. DS needed to use the restroom and I told him to go and he happily went (I could see it was empty). My mum got up to bring him and I stopped her saying I'm trying to teach him independence and he's well able to go on his own. She couldn't understand why I'd allow my 6 year old to go to a public toilet on his own. If I was somewhere where the toilets were out of view or that there was a women/men's toilet I'd bring him in but in the next year or two he will become too old to use the women's toilet even accompanied with me and will have to start using the men's on his own anyway. My mum wasn't happy about this at all. I'm wondering do you think he's too young.