the ball is in your half court

this expression means

it is now up to you to decide on what you want to do/what decision to take

N.B : this phrase is a direct English translation of the french (specifically of France) expression "la balle est dans ton/votre camp"

mother: Angela, why are you doing drugs? I now give you two choices: either you leave your current boyfriend Brandon and the drugs, or you can move in with him; in which case I will want to have nothing to do with you. The ball is in your half court.

Angela:I would like to commit suicide. Wtf? You want me to choose between the devil and the deep blue sea?

mother: that's not an option. i am taking you right now for a psyche eval.