I have only heard, 'auntie' used as an endearing term, and I'm from the U.S. Generally, 'aunt.' is more widely accepted as the common term, whereas it seems to me, 'auntie' has the more personal connotation. The translation makes sense to me, as I've heard, 'tantine,' as a direct interpretation of the more endearing word.
Just to add for cultural sake, here in Canada, the word "auntie" is typically reserved solely for the youngest family members or used as an endearing term/nickname. For example: Should an adult refer to or present their aunt as "This is auntie Tina", one might assume they were being immature intentionally or were, well.... let's say not wanting to appeal to the adults or the educated in the room. Once one becomes of age, they use "aunt" and only "aunt", typically. Whereas "auntIE" is the equivalent of using "momma" instead of "mom" or "mother". Or "daddy" rather than "dad", "father" and so forth.
Be aware that while many UK English speakers use "auntie" or "aunty" in place of "aunt", this presumes a co-opting of "tante" = "aunt". The Oxford French Dictionary describes the familiar terms "aunty" and "auntie" as "child language" which corresponds to the French, la tantine/tatan/tatie/tata. Duolingo understands that large numbers of English-speakers use the more familiar term every day but also wants learners to know that there is a difference between the standard "tante" and the informal "tantine/tatan/tatie/tata".
Right! The point is not that people don't use "auntie" or "aunty" regularly in English (even to the exclusion of "aunt"), but that, when they do do, they are using the equivalent of « tantine » not « tante ». Or to put it another way, if they see a French sentence with « tante », they should come to terms with the fact that it's French that doesn't correspond to their preferred way of speaking in English.
USUALLY it means wife if it's a possessive before the noun, and woman if it's an article before the noun. But of course it's not always the case. Sometimes you just got to go off of context . You would never say "the woman of my uncle is my aunt" it's just not correct. so in this case because of context you need the put "the wife" it's still possessive in a way just not the way most people are used to the whole "Ma femme" or "Sa Femme".
"De mon oncle" makes it "of my uncle", which turns it into a possessive sentence. therefore it would be The wife not the woman.
Hope it helps
Whenever you have a family reference, you interpret it as "wife", not "woman". More importantly, the syntax of "the wife of my uncle is my aunt" is not idiomatic (natural) in English at all. It is a common joke among English-speakers studying French to say "the wife of my uncle is my aunt" to mirror the French "La femme de mon oncle est ma tante", but English almost never uses that structure. We say "My uncle's wife is my aunt."