Board Thread:Theories and Rumors/@comment-36492994-20180825164455/@comment-34175192-20180826001951

Warptoad wrote: Seriously guys, Antonia is an actual person who asked to appear in the show! They wrote her in, but it's most likely just a quick cameo. They didn't completely rewrite whatever they were doing just for her. This is probably the most likely answer.

She's just a girl who was really sick and the creators put her in. Like Warptoad said it's probably just a cameo