Your girls need a good dose of Tough Love. Sorry it might seem harsh but thats what they need right now. First and foremost do not give them money. They are using it to buy drugs. Secondly get them into rehab. If they won't go then they must leave your home. They are destroying their lives but that doesn't mean they can destroy yours. You must tell them you love them but you don't love their behaviour and you are doing these things because you love them. They won't believe you right now but hopefully one day when thy are back in the land of the living they will remeber what you have done out of love.Try contacting your local Government Mental Health Service about the "Tough Love" Program. You are going to need all the help and support you can get to deal with these girls.

I'm not much older than your daughters; but I have grown up with siblings and also my parents dealt with the same type of situation with my brother. You're number one goal as a parent is to see your child succeed in life. Every parent wants their child to grow up and be the best they can be. People are going to tell you how to raise your daughters; but in all honesty we don't know your daughters and we don't know the kind of home life, or things they have been around for the last 15 years have effected them. Only you as a parent do. It's very hard on children these days, with peer pressure, anything goes. Especially in todays society. You as a mom, need to make sure you are setting an example. A lot of times children, will say " Well my mom and dad do this, so it's okay for me to do too." There needs to be a fine line drawn between what is acceptable for an adult, and what is acceptable for a child. Plain and simple, a child does not have the same mindset that an adult has. If they did, we wouldn't need parents, and the legal age wouldn't be 21. Kids will be kids, and kids will get in trouble and test the bounderies. We all do, and we all have, and we all have learned in the end. Don't give up on your daughters; there is a reason why they are acting like this. Supervision, Attention, and Boundaries. Keys to a teenagers life. Despite how they might act, they still love you, and want your attention. This might be their way of getting it. Re-evaluate their friends; "If Sandy jumps off a bridge, would you do it too?" Most likely yes. As dumb as it sounds, yes they probably would. Friends always have an impact in your life. Get them involved in sports, dance, drama, anything to get them away from drugs.

I'm not sure momma how to help you out; My advice would be to show them no matter what they do you still love them. Love conquers all. Not being a softie, but love. Everyone needs it.

i know this may be too harsh for many parents to cope with but the discipline system is called tough love try www.toughlove.org this is a system set on the idea that you do not and i repeat do not let them get away with with what they are doing you withhold all money if they need food by all means any parent would not let them starve but do not give them cash you buy food and open all packages and keep all receipts so they can not return food if you pay rent so they have a roof over their head's go to the realestate and pay the rent personally!  You let them deal with the consequenses of their actioms themselves if they do drugs you report them to the police you have them deal with the punishments do not bail them out or support them in court and let them learn for themselves and also let it be known that in no shape or form will you not tolerate their disrespectful  behavoir towards you as you will not let them do it to the person that loves and cares for them and have brought them up and taught them how to behave properly it is their own fault what they do at this age all you can do is let them know what is respectable and if they decide when they are old enough to make up their own mind to do otherwise it is their decision not yours!

I was one of those teenaged daughter once upon a time, and I dont think I would have changed if it wasnt for falling pregnant, and im NOT suggesting thats any sort of answer...

BUT you could call crisisline, or a similar councilling service and ask for the best way to approach them, also giving them money will only feed their addiction.. i dont know if u should cut them of from all money either cos that could lead to stealing..

maybe talk to them about why they are acting this way, they sould like they need some motivation to make a future for their selves, maybe get them into a sport or hobbie or a job.. like a traineeship or something..

i know i regreted the way i behaved when i was young and apologised to my parents, it wasnt till i had kids of mine own i realised the world didnt revolve around me...

 its such a hard issue to deal with but dont give up on them there are plenty of people that will be willing to help...

here are some websites that might help

http://www.familydrughelp.org.au/

http://www.cyh.com/HealthTopics/HealthTopicDetails.aspx?p=114&np=141&id=1747

http://www.cyh.com/HealthTopics/HealthTopicDetails.aspx?p=114&np=301&id=1869#14

hope this helps...