@laurengranger08 technically nobody actually knows their real names so she could actually use any name she wanted for them. Nobody knows their names as J.K deliberately kept her family in the background, the reason being that we knew alot about the ron’s family so to contrast upon this she allowed us to know little to no info about them (including us not knowing their canon names). In fanfic logic, any name can be used because fanfics do not have to be canonically correct, however if we are talking about the actual book / film series, every harry potter fanatic knows nothing about their real names.