No evidence to suggest Hunter did that too Drew. Unlike Sterling, Drew wasn't an enemy, wasn't getting in his way and most of all wasn't slowly killing him. Drew was definitely in control of her own thoughts if she was arguing to Hunter about drugs.
As for what side. Her own it looks like. She also wants the women in the house, but doesn't want to use the drugging method. Yes, she did drug Brenna, but that's because she herself was drugged. She is shown to care about the women in the family like when she dropped her date night to listen to Brenna. She as far as i can tell, is her own third party.