For many occasion and with the study I carry out. I find that many children from the ages of 4 to 13 years, are calling their biological mother 'Aunty'.

Many of these children come out though wedlock.
My question is 'can we say is a right name to called?

Some of them learned it from their house helps or maid who they grew up with. My brothers and I fall into that category.

Dats true and some mothers dont mind,i av a sister dat her kids call mumy,but some tyms dey call her aunty funmi wen dey r jokin or jistin

My thoughts was that such occurs only with children that didn't spend their childhood days with their mom. Eg kids that spent their first to ten years with grannie or aunt. They tend to refer to whoever they grew up with as mom(if they are not being maltreated) and their biological mom as aunty.

@metalgoong,your mom was cool with you guys calling her "aunty" ?

It is common among the locals in my hometown..and tied to funny sentiments.
Some say "mummy" makes them feel old and would prefer their children called them "aunty"
i know a couple of friends who call their mum aunty too.