I've been fortunate that my children have never stolen from me and I've never stolen from my parents BUT I was fortunate that I've never felt in need, neither have my kids.
My best friend however has just gone through the same thing. The difference is that it is her son. He stole £100 from her purse. Frankly, I'm not surprised at all! He has just turn 16 and has low self-esteem and has always seemed desperate to be accepted by his peers and like them. He's very materialist and seems to think that to be respected, he needs to have the latest things. His parents, I feel, are very hard on him. He doesn't get any pocket money, he only gets a few £££ if he does extra work -in addition to normal chores- and when he turned 16, he was told that he wouldn't get anything at all because he could just get a job. As far as I believe, he has tried, but as we know, not easy at 16, and his issues with self-esteem doesn't help.
Anyway, it has turned out that he stole the £100 to buy the latest FIFA Xbox game. Supposedly, when he broke down in tears and admitted it, he said that 5 boys got together and they decided to randomly select who would be the one buying it (and something around that others could then access it, I don't get these things) and he got selected (which we all suspect might not have been so random at all). He was desperate to make them happy and be fully accepted in the group and had hoped to quickly get a job and get some money. Of course that didn't happen, they pressured him, and that's how he got to steal the money (the rest spent on pizzas to celebrate when they got the game).
My friend was furious and very upset, but being mum, telling him that he couldn't come in HER house wasn't even a consideration. After some shouting and screaming, they talked and the above came out. They have agreed that she was going to help him with job applications, walking into shops etc.. and he will repay with a big cut of his pay. She is also taking him to the GP to hopefully sign him up for some counselling to work on his self-esteem.
Sorry for the long post, but I have found this thread so sad. Most kids who steal do so because of some MH problems, which often come from issues at home. It's easy for SM to talk about THEIR house, but it rarely is so, it's usually at best their and their partner's house, and by proxy, their SCs house too. That kid seem to have nowhere to call home, nowhere to get proper parenting, yet OP seems to consider herself as the victim...