They do the sleepover at Willows house because what good parents let their children stay at a house with a well known criminal?! Readers learn Willow parents are very loving and smothering but openly criticize her for her bad grades and for not trying hard enough. Openly compare her to Gus and how he is younger but excelling at the same level as her. Learns she's been lying saying she's part of a study group to better her grades when in reality she's been at the Owl House. Parents have no idea she's been learning from Eda, they just think she's starting to question things.
An: update a day as per promised