Vasu, if age is irrelevant and family structure comes before anything else, doesn't that mean Monghi is also an aunt to Hiten, actually to all of DM's children?? But isn't it absurd to expect 3 twenty somethings to treat a 10 year old as their aunt?? But they are supposed to treat Khemi & Santo as their mother and aunt. Well, that's just hypocratical! The rules should apply to all three sister or to none at all.
BC, this is quite normal in large families where there's a big age range in brothers and sisters. Example, my MIL are 11 brothers and sisters. Older siblings were married long before the younger ones even entered school. Result, older siblings already had children when uncles and aunts aren't even married yet. To take it further (and it gets confusing) these older siblings' children have children that are older then the younger sibling's children who are uncles and aunts by relation.