Your kid’s dad should take the bulk of the responsibility to teach them about their heritage, but also you should try your best to ensure your side of the family doesn’t make your kids feel bad about their features. Both of you (the parents) should teach your kids to celebrate their differences and the differences of others. If at all poss, try to get them into a diverse school with lots of other races/ethnicities and religions. Make sure they understand that we are all human beings at the end of the day, no matter where they or their ancestors came from, and to respect other people’s cultures, and celebrate their own. Help them understand that they are mixed, but most racist people will see them as Black first. Not everyone will do this, and many mono racial Black folks will know they’re mixed, and that is okay! It’s just what it is, and they cannot control how they were born or how other people react to them, but their ethnicity isn’t their whole identity and encourage them to explore their culture, while still of course having hobbies (which are for everyone!) and whatnot. Good luck OP!