Lox, two things in your last post I want to address...
You can't fathom her behavior - that is because you are expecting her to be rational, sensible and trustworthy - and drug users are not rational, sensible or trustworthy!!!   You have been in love with a fantasy of what you wish her to be, not WHO SHE REALLY IS! It is hard to accept, but you have to face the fact that you have allowed a person to stay in your life who is dangerous and untrustworthy because you HOPED she wasn't. Get the fantasy of her out of your mind and face how she really behaves. Don't believe the nice things she says or does... it is all a manipulation to get away with the other crap she does.

I've been in your shoes, so please read this through a few times.
The other thing is that you were there when your little girl found drugs on four occasions. WHY was there the second, third and fourth occasion? Not because the addict didn't stop the drugs, it is expected an addict won't stop the drugs, but because you stayed around the addict with your daughter for it to happen again. I'm not trying to put a guilt trip on you, I know how UNBELIEVABLE their behavior is, so sometimes we go into denial that it could be happening or could happen over and over. ACCEPT reality and see that it will keep happening. This is where a professional could help you get in touch with the reality of what you can expect if you keep her around yourself and your daughter. I remember staying around someone who eventually threatened to kill me, just because I couldn't believe it was happening to me. It seemed unreal, but I'm telling you, the irrational and dangerous behavior from an addict is what you have to EXPECT. Don't expect her to act normally. Expect danger, and get your girl and yourself far away.

Take care,

Alice