""Nobody in the UK would say , "Of course I love you ,I'm your mum ,am I not?" "

They certainly WOULD say that. But more often, they'd say "aren't I?". Even though, strictly speaking, it's not correct.""

True Sue, or even ain't I?

Amn't is a term I have heard, but rarely, and only in a very few dialects.

But then I'm a Southerner, so everything I say is suspect, north of Birmingham.

Don T.