1/4 black caribbean, 3/4 white british baby girl.

I'm currently pregnant and I'm white british and my other half is mixed race - half black Caribbean and half white british. That means our little girl will be 1/4 black and 3/4 white. I would still put my little girl in the mixed race ethnicity on a questionnaire, but a friend said they would put white for her as "a quarter black isn't enough to count as mixed race". She is mixed race herself. I was wondering if anyone could let me know their thoughts or what they've done in the same scenario? I want my little one to be proud of her background and feel like putting white ignores her heritage in some way.

Also, on a sidenote, my other half isn't as in touch with his black caribbean family so I can't really ask questions about this. I myself don't really know how to care for little ones hair if they have afro hair so I was wondering if anyone had any hair care advice as google isn't getting me very far and I don't want to do something wrong as I know it can be really difficult to care for - especially when they're babies.

Thank you 😊 Xx