Aunts. People normally refer to their "auntie" as just aunt (at least where I'm from) , so that might help you remeber the plural form. Aunt with an "s"
I've seen it spelled either "Aunty" or "Auntie". I think the second one is probably more correct, since it didn't get underlined by the spell check program and the first one did.
Latches.
daddies.
Clouds
circus's
slides
axes
That is the correct spelling "princesses" for more than one princess.
I think perhaps you are trying to spell countries, as in more than one country.
Trophies
spell it out - there is more than one ADEA
One activist. Several activists.