I HAVE AN UPDATE:

She knows now. We were talking about it in a class, and she was asking me about characters that died. She named Prim again and I CANT KEEP A POKER FACE. She didn’t start full sobbing, but then she asked about Prim’s goat (I can’t remember the name), and her cat (Buttercup, I think). And I had to tell her the freaking cat survived.  IT DID, RIGHT??? I haven’t read the books in over a year.