My mother-in-law stole my money and refuses to pay it back

It's just me and my husband in the house. We're currently building a house and so we're living with his mom. We're currently in a really tight spot and we can't afford to move out right now, but we should be able to in a couple of months. We've been paying rent and we also chip in for groceries and utilities. I don't even care about the money but I care about the principle. <br><br>She's always been really horrible towards me. She didn't want my husband to marry me. She's always making rude comments about my job or appearance. She never thanks me for anything. <br>And she's always taking my stuff. I've lost count of how many things I have lost, that she suddenly had. So I've had to stop leaving anything in shared areas or she'll 'borrow' it and never give it back. <br><br>Each time I buy groceries I label my food. I've caught her multiple times eating my food that I paid for. I don't want to tell her how to live her life, but I've seen her turn down decent food because it's not from this brand or that brand. I just buy whatever is on offer. My husband has also told her that I don't like eating with others and that she's free to make her own meals, as she prefers to anyway. But she still raids my food and she still complains about it. <br><br>I went to make a cup of tea and she had my tea. I was so pissed off so I told her that it was mine and she just walked past me with my tea and went to her room. I told her that I paid for it and she said 'I'm not paying for it, you're paying for it'. I was so angry, but I let it go because it was just a pack of tea that I could easily replace. <br><br>The other day I was looking for my bag for work and it was gone. It's an expensive bag that my mother bought me before she died. But she told me that it was hers and she bought it. It's literally the same bag that she saw me carry every single day for the last year. I looked around for it and found it in her room. I took it and she said it wasn't mine. I told her I paid for it and she said 'where is the receipt of you paying for it?' <br><br>So I decided to be proactive and keep receipts of everything that I buy. And then this morning I woke up and my headphones were gone. I asked my husband about them and he told me that she took them and said that they were hers. I found them in her room and it was literally the same box that it came in. She just put the box back under her bed. I emailed the company and got a receipt. I asked my husband to tell her that she needs to give me back my headphones and she said that they're hers. But she emailed me the receipt and told me that it was only a proof of purchase and it wasn't proof that it was mine. <br><br>I know that she's not going to stop. She's so petty. But I don't know what to do. It's not just the money. It's like she's taking my identity with her. I told my husband that I just want to buy my own house so that I can be in my own space. At least then I can keep my things. But that's months from now. <br><br>My husband asked her to pay for the headphones back and she said that we have to pay rent or get out. It's literally the only thing that she asked for. She didn't ask for groceries or utilities. Just rent. And she's been paying less for rent than we have. So I told her that we're not paying rent until she pays for the headphones. And she's been in her room since. <br><br>I'm just really annoyed and I don't know what to do. I have receipts for all of my purchases but it's literally just proof of purchase. It's not proof that it's mine. She already took my tea and my bag. Now she's taken my headphones. How do I prove that it's mine?<br><br>[Edit] You guys are amazing. I'm literally crying reading your comments. I really appreciate all of you. I feel like I've been validated. My husband and I are thinking of just moving out. It's tough but I just feel like it's better for the both of us to leave as soon as possible. <br><br>[Update] We moved out. It was hard, but we made it work. It's been a couple of months since and things are fine. We've been keeping in touch and she seems to have moved on. I can't believe I let it get this far. I should have left a long time ago. I'm glad that I did in the end. Thank you all for your support.