1. Your mum's mum is your grandmother.
2 You sister's son is your nephew.
3 Your dad's brother is your uncle.
4 Your son's daughter is your granddaughter.
5 Your brother's daughter is your niece.
6 Your dad's dad is your grandfather.
7 Your uncle and aunt's children are your cousins.
Ответ: nephew, uncle, granddaughter, niece, grandfather, cousins.