The School for Good Mothers by Jessamine Chan

When Frida leaves her young daughter, Harriet, home alone for a few hours, someone calls the police. Harriet is placed with Frida's ex-husband, Gust, and his girlfriend Susanna while it's decided if Frida will lose joint custody. In order to possibly get Harriet back, Frida has to participate in a year-long residence rehabilitation program to learn to be a better mother. She and the other mothers will be watched and graded throughout their time there. The program itself is isolating, with the mothers only being allowed weekly phone calls with their children if they have earned it--the standards set being impossibly high. Those standards ultimately determine whether they will get their children back, which sets the women even more on edge. The School for Good Mothers soon becomes a chilling dystopian tale that's unputdownable and gives the reader a lot to ponder.