This would indicate that maia wants to be referred to as "it" as the subject of a clause and "she" otherwise.
“they/he” and “it/she” indicate alternatives, whereas “she/her” indicates different cases.
Do you mean that instead of saying "it's her apple" you'd say "it's she apple"?
Correct; it is massively ungrammatical.
> Do you mean that instead of saying "it's her apple" you'd say "it's she apple"?
No possessive form is indicated. But instead of saying "I gave it a dress", you would say "I gave she a dress".
Edit: looking at other comments, it seems like it might not be the correct explanation after all?
Some people desire a single set of pronouns, and indicate this using the nominative/accusative pair (she/her, they/them, ze/zer).
Other people accept either of two different sets of pronouns, and indicate this preference using the two nominative forms separated by a slash (she/they, they/he, and apparently, it/she).