['So my mom signed me up for therapy tomorrow and only just now decided to tell me about it today.', "That seems a little odd.. It sounds like you guys don't have the best communication. Did she say why she didn't ask you?", "Nope, she didn't say why."]
I see. I'm not sure that's healthy, but it's also not my business. I hope that for both your guys' sake you are able to communicate a little more properly in the future. I don't think therapy on its own can work unless everyone is willing to listen to each other.
Two weeks ago my mom signed me up for a therapy session without telling me in advance. She never respects my time and assumes I sit in a room and stare into the empty void all day. This made me angry, and I almost impulsively refused to go but after a few hours on the advice of a friend agreed to let her help me.