Oh dear, that is tough. I can imagine how hard it is on you. I would get together with the rest of the family and talk it through. Then maybe confront the one who is stealing. You can't carry the burden all by yourself and besides you don't want others to think that it was maybe you who was stealing. It tells you a lot about the character of your relative as well...who else is s/he taking advantage of and how to trust that person for the future. The other thought is that maybe s/he is doing the same thing to the other family members. You can let that happen. Good luck to you.
RE: I need your input
The second last sentence was supposed to say...You can't let that happen,lol. Sorry.