As soon as she comes to you asking questions about caring for it, I would tell her to call and ask her grandma. If she has an allowance make her pay for her own products etc. Let her find out the hard way what being sneaky will get you. Darn that is messed up. Q
doing this!! im hiding all my hair stuff and my dryers.
That was a bold move. Grandma, dad and your daughter being in cahoots was wrong on so many levels 

Not to be disrespectful - my dd is the same way, it's a constant battle getting her to understand that she MUST control her eating. She's on the verge of being chunky.
My family used to joke that dd needed a perm when they saw me combing through her thick kinky hair, but if they actually did it w/o my permission.....

the ladies are giving me wonderful advice and I thank you all so much for listening to me vent about this