I agree that you must lock everything up. I also agree that she must work to pay off everything. She also must lose ALL privileges. I do mean ALL. THis meansI ALL electronics are GONE. NO computer usage at home or school. Tell school that she is to have zero use of the computer because she uses it for theft. Yes, it is not fun, but you didn't steal so it is not your shame. It is hers. If they tell you that they cannot teach her without the internet, tell them that is not your problem. They can give her alternate lessons of some kind. She just cannot put her hands on a keyboard.
With summer coming up, lock up the computer in your trunk. You can actually put the router in your trunk each morning before work and take it with you so she cannot go online while you are gone. Take any tablets, phones, etc... that she has also. I would not even leave an e-reader for her. she can read a book. Take the tv away by unplugging the cable box and removing it also. Keep ALL financial paperwork in a safe that you keep away from her. Let her know that you will NOT be allowing her to get driving lessons at any time in the near future due to her theft and impulsivity. She is in no way ready.
I suggest she not have a purse, not be allowed to have any money that you or her father don't know about (if you don't know about it ahead of time, it is forfeit to you), she cannot go into stores alone, she cannot go to stores with friends, she cannot go into stores with anything in her pockets, she cannot go into stores without you checking her pockets, she cannot walk away from you in a store. She cannot go into the bathroom while you shop. She must wait until you can go with her.
No, none of this is fun for you. You don't want to treat her like a toddler. I wouldn't let her go out with friends. I woudl keep her grounded all summer for a theft of $1000. Especially if it is multiple thefts adding up to that amount and no real remorse. I would be taking her to the animal shelter and other places to volunteer when you have time. Places she can clean up things and do menial labor and hard work. That is what the court would have her do as community service. At least in my community that is what would happen if you pressed charges against her, unless they sent her to juvenile jail which is the worst thing they could do. Juvie would just make her a worse criminal and would not teach her anything. One of my kids had to do community service and I had to go with them. They were underage so I had to sit there the whole time. I chose the animal shelter so at least I could play with the animals while my kid cleaned cages. Then after a birthday my kid was old enough to work at the Y without supervision. So for 1/4 of the time I didn't have to sit there.