You'd have done better to convince her not to hit me with that book.
Merlin's beard. If I try to cast any spells on her she's going to get upset, isn't she, because she thinks I'm some imposter. She's right, I'm not her uncle, but she'll hardly believe the truth.
I suppose I might recite the family lineage to her. It'd prove I was a Black, at least. Nobody would bother learning all of that unless their parents made them.