so when they both died in battle, harry (as godfather) should have brought up teddy (or tommy) but in the nineteen years later it refers to teddy in a different way :
"snogging victoire (who i guess may be bill and fleurs daughter or something?)
and they said he comes to dinner 4 times a week and then harry says "why dont we invite him to live with us"
so teddy is not living with them and who is looking after him?!