Re: Aunty???
I think it has to do with you being married. They don't realize a younger person can be married too. :D I actually knew a girl like that. She used to call unmarried (older than her) girls "baji", and as soon as they'd get married, they'd transition into "aunty" in her dictionary. She'd admit to it too! So as soon as she herself got married, a lot of people started teasing her about transitioning into auntyhood. :D
So yeah, next time she calls you aunty, tell her you're only 20, so she should just call you baji...if anything.