What's "in charge of" mean?
Native speaker’s answer
Rebecca
To be "in charge of" something or someone means to be responsible for or to manage something or someone. In this case, the speaker has used this expression to mean that Monica is now responsible for her romantic relationships. In this case, Rachel used it to jokingly imply that she is not good at managing her love life, so she wants her friend to do it for her. Ex: I am in charge of my whole family as I'm the oldest. Ex: As the manager, I am in charge of the five people.