I’m so confused

more understandable in the novel but ilya has just found out her mother has been poisoning Silvia with something that won't kill her but will make her veeeeeery weak. this is cuz Silvia had started going to the academy, which made her very lively, and the mother doesn't want Silvia to leave home, so that's why she poisoned her, and the mom killed herself in order to not have to face the consequences. hope that makes sense

Yeah that made sense