Hmmm...well, let me start with the disclaimer that my Difficult Child is in jail now, and that all of my various contracts/management plans/support obviously were ineffective, so take this with a grain of salt.
But...I feel like it may not be fair to have rules hidden behind rules. You laid out some rules and she is following them. Going out with a friend who is clean to do something that she is paying for and she is not asking you to be her chauffeur all sounds pretty good!
It is OK to remind her about being sure to choose company that supports her goals.
But my own reaction is that you pulled out a hidden rule and then got in a fight with her over it.
How do you interact with her without a full blown panic attack?
Say..uh, Difficult Child, since you asked, I'm just thinking that hanging out with meth-addict sis does not fit with your goal of hanging with healthy people. But you are a grown up and I trust you to make the best decisions for yourself. Bye!
Then if she breaks any of the actual rules you agreed to, back to the street she goes.
On another day I might take a different stand and invoke the "no sketchy behavior" rule that the therapeutic boarding school we sent my Difficult Child to used...they got tired of all of the smart destructive boys finding ways around the rules (you never said there was a rule against dismembering roommates! How was I supposed to know!), so they had a rule that sketchy behavior was not tolerated. I kind of like that rule, and as a general rule if I invoked it Difficult Child tended to agree that what I thought was sketchy was indeed sketchy.
However, I repeat, he is in jail, so obviously my approaches were in effective!
Difficult Child's twin sister, who was quite the smart challenging risk taking smart mouthed Difficult Child herself for a while (did I tell you about how she was expelled from her extraordinarily selective superb and FREE magnet school because she brought vodka to the class picnic in a water bottle? IN 8TH GRADE??? but I digress....), is now a totally fabulous 21 year old, about to graduate from college, has three job offers in a field she loves, and is moving to yet another state with her equally nice and employed college grad boyfriend. She no longer uses drugs of any kind, although she drinks some and smokes cigarettes to my distress. But she is honest, diligent, kind, and respectful. She says it was a turning point for her when I started responding to her questions and attempts at trickery by saying "yes, go ahead, I trust your judgment". She said she was actually totally freaked out..."what???MOM TRUSTS MY JUDGMENT???? I better think about this again if she isn't going to keep me safe by refusing..."
I started doing that the summer before she went to college 2000 miles away, since I figured in a few short weeks I would have no idea what she was doing and would have to...trust her judgment.
I think that all worked out because at heart she is not a truly messed up Difficult Child.
If they are truly messed up Difficult Child's nothing you do will make any difference.
So either way...you can say...you know the rules, I trust you.
And things will play out as they must.
Good luck.
She sounds a bit bratty but overall doing quite well. That is pretty normal for an 18 year old girl living at home.
Hugs
Echo
