Welcome! You have found a great group of people and we truly have been there done that, so we don't judge.
YOU are an adult and so is your child. You are responsible for your daughter financially but that only means while she is in yoru home. You can't kick her out but you CAN make ANY rules you want in YOUR home. This included curfew and time she must be up and out for the day. I would tell her she has to EARN every luxury, incl food she likes. Provide basic basic food with NO condiments to her. Put a chain around the fridge and a lock on all but ONE cabinet where HER food is. YES, this is unpleasant for you to see and a hassle. The other option is to keep all food that is nice and yummy in YOUR bedroom or locked study. Make sure it has a sturdy door and a deadbolt lock. Keep the keys on your person at all times.
Take the tv, radio, etc... and put them in rooms with locks on the door(s) and keep those locked. She wants to watch/listen/use a computer/whatever? She has to have a job, a clean drug test (and she needs to pay the cost of the drug test out of ehr paycheck as a consequence for NOT being trustworthy and using drugs), and have a clean room.
Let her know that you no longer believe in privacy for anyone under 21 - from the parents. Search her room often. If you find ANYHTING like drugs, paraphernalia, thngs you think are stolen? Call the police.
It is NOT time to worry about her record. It is time to worry that she will hurt you or do this to someone else and get SHOT for trying to steal from their home or business. MOST states allow you to shoot someone stealing from you or breaking in. I know that was a big worry at one point with my brother (who did get shot at several tiems, unknown to our parents).
Set a curfew and if she isn't home by 10 or 11pm, the door is locked and you don't open it. At the time you leave for work she must be up and out of the house, pref to work or school. Be loud, obnoxious, SING if you can sing badly (Children's songs like Barney are great to wake them up and make them leave - I am serious, it works magic with my kds, lol.) You cannot force her to live at home after 18 and the GOAL is to get her to leave the home. As long as she CAN move back home, she CANNOT force you legally to pay for her to live outside of your home. By Can I mean her room is there but the rules are the same - she doesn't have to liek the rules, she just has to have a place she CAN live in in your home.
Most importantly, think about what her life will be like in ten years if she does NOT learn that she cannot steal and harm people and property NOW. At 18 the courts will show some leniency. At 25 or 28 they will NOT, esp if she has continued to do these things. If she gets into trouble she will most likely have a PO and they will impose rules nad monitor her and there will be consequences. Usually you can have a record expunged if you clean up your act and stay clean for a period of several years (here it is 5 and I know one person who had 3 serious gun related felonies expunged after rehab and 5 yrs of no charges/involvement with police.
Right now your daughter KNOWS that you don't want her record/future messed up. She COUNTS on you protecting her and not calling the cops. She feels totally free from real consequences and that you will rescue her no matter what. You need to do the tough thing and make her face some real consequences. She is NOT going to straighten up until you stop protecting her from the consequences of her actions. This means allowing her to feel the REAL WORLD consequences of stealing and hurting people and damaging property, which means calling the cops and pressing charges. WHile in custody they will give her the medications she is on, and she will be cared for. it isn't fun but it isn't supposed to be.
PLEASE attend alanon, or families anonymous meetings. Also read Boundaries, by Townsend and Cloud, and Parenting your Teen with Love and Logic. Love and Logic (L&L) has a number of books and this is written for parents with teens. While your daughter is an adult, your state laws (which are stupid because you have NO ability to force treatment but every responsibility for housing and feeding your daughter) are forcing an extended teenage period. I think it would be a very helpful book.
Your goal here is NOT to be mean, but to make her become a productive member of society. You have effectively NO tools for delivering consequences other than not providing luxuries nad not giving her cash (with dirty drug tests I would not ever give her cash for any reason, or a credit card. she needs a job if she watns cash). The only real tool you have is to press charges. It may not help right away and you may have to do it more than a few times, but in time it will teach her that she cannot do thngs to you.
I do think the books and meetings will be a big help and support to you, as will we. We understand how hard this is, and how upsetting. We also know that it takes small steps to get to the point where you can do things like press charges.
by the way, you DO know that by financially responsible it means responsible for the things that welfare would provide, NOT the luxuries taht most of us have in our homes? NOT for whatever she wants to do or to pay her bills if she wants to move out or lvie elsewhere? In most areas, foster kids get $50twice a year to buy clothing and shoes, they have 4 pr pants, 7 shirts, 1 pr pajamas, 7 pr socks, 1 pr shoes, 1 coat. That is IT. I got this list from a social worker at a psychiatric hospital where my son was a patient for a period of time. A bedroom has a mattress, sheet, blanket (ONE), pillow (ONE), a light (ceiling light usually), and their clothing - a box is fine for storage, a dresser provides places to hide things. That is IT. Food can be super basic - cold cereal (corn flakes or whatever is the cheapest), peanut butter and jelly sandwiches, ramen noodles, oatmeal. The basic to live on. You are NOT required to provide tv, computer, phone or cell phone, car, cookies, trinkets, jewelry, etc... With her medical issues you do have to provde medicine and needed appts, but if she refuses therapy, medications, to see the psychiatrist, then you don't have to provide them. We know you would far rather provide them, but if they are not helping, and it is a fight, then she needs to experience the consequences of that choice.
It isn't easy to get to this point. But it is helpful for her to realze that she is NOT entitled to the stuffshe wants and that she MUST live by the laws that govern everyone, even in your home. if she cannot learn this by the parenting you ahve given her, then she needs to learn the hard way, which is through police involvement. It isn't fun. But it is likely the ONLY way she will have a life that has any quality.
Work in baby steps. Get the books, find a meeting of families anon or alanon or narc anon. You want the family meetings. As she is having dirty drug tests, she has a problem with substances even if she won't get treatment. This means the entire family has a problem, and the BEST way to get things to change s to get help through a 12 step program or another family recovery program.