My parents in the past.
Laila was throw, accidentally of course, through a portal. She had no clue what it did at the time, but when she wakes up in a different Amity Park, she discovers that the portal sent her back in time.
So, she has to get back to her time, not change time, and not let her parents, Danny Fenton and Sam Manson, know who she is. Piece of cake.