Soooo... is it official that the older female MLP fans are called Pegasisters?
not really. the brony term was originally used for any male fan that watched the show, as time has gone by fans just considered it a gender-neutral term. the "Pegasister" term came later on, some people thought to use it to define any female-fans of the show.
some are against it (both genders that is), some think it separates the fans/groups them in a way that might make them feel insignificant or something, some are for it, and others don't care one way or another. some girls like to use it, some don't. it's a personal-preference thing, I think.
I don't think it was ever used for age-groups.
