Auntie would be the usual spelling of the familiar form of aunt.
No she isn't an Auntie
auntie = tía
They talk about their daughters.
Auntie is capitalized when it precedes a person's name. Example: Dear Auntie Carol, Her Auntie Luisa is attending the meeting tonight.
The cast of Auntie - 2013 includes: Marcia Burrowes as Auntie
Carries auntie
You can say "shangazi" in Swahili to refer to auntie or aunt.
Auntie BEEB - the BBC
My Young Auntie was created in 1981.
Auntie Freeze was created in 1986.
Auntie Jen is 5' 6".