The line between baji and aunty is so thin, you could just never know. And then behavior plays a huge part in it too. I'm 23 and I get lost sometimes in what I should call a 30-something... theres some 30 year olds that are just totally normal and sisterly and you have no problem calling them baji even if they have 3-4 kids, but then theres a whole different breed of women in the same age group that act like such ammas, the way they dress, speak, carry themselves, and even how they look that makes them look like such AUNTIES that I really just dont know what to call them cuz they get all upset at you calling them baji.
Me personally I love when lil kids call me aunty instead of baji, I think its cute :)
OMG YEAH!! When I was 12 I used to call this 21 aunties cuz she mostly talked to my mom. She also has 2 kids at that time. She never minded. As I got older my mom noticed that i called her aunties, and my mom was like don't call her auntie! She's your baji. And this aunti/baji was NICE - she joked nah it's not necessary---nah it's fine, but i quit calling her aunties anyways and now she's like call my sistaaaaaaaa. she's a fun lady!