Answer:
Usage of singular 'they', 'their' and 'them' is the most common; and ze, sie, hir, co, and ey are used as well. Some others prefer the conventional gender-specific pronouns 'her' or 'him', prefer to be referred to alternately as 'he' and 'she', or prefer to use only their name and not use pronouns at all.
Probably not right but...
Hope this helped!
-RosemaryANdStars