Rubrick

I think your aunt is right. The children are just misinterpreting what they see as an unusual pronunciation.

I find it is quite common here in Edinburgh amongst young children to regard any English accent (I mean any) as "posh". I've noticed this when the children are asked to play certain characters in drama.

Several people have told me that as an English "Northener" it took a long time to be regarded as a "Southerner". It is technically true on the compass but being from the North rather than the South is about much more than points on a compass! I imagine it is true for people in other countries too.