With Ali's mom back in Rosewood, it's going to leave the Liars with even more questions surrounding whether they really did in fact see Alison during the season 3 finale.
Executive producer Marlene King says that [Ali's mom's] return to Rosewood will spark even more debate amongst the girls about whether they really did see Alison during the fire last season. "She [was] redoing Alison's room," King notes. "Is she crazy or [is she] getting ready for Ali to come back?"
Source: TV Guide