One of the Malfoy's married a Potter way up in the family tree, but there are several ways they could not be related by marriage. So it might be incest but isn't confirmed to be
Also, Teddy and Victoire is technically incest; 4th cousins, once removed. But no-one brings that up, when it's canon. Drarry being incest just isn't. Nor is Drarry itself, but eh.
