Don’t leave things that are important to you lying around. My Dad used to say “Don’t tempt an honest man”. By that he meant don’t leave things lying around that might tempt someone to steal them… You might try bring this up to Dad to see if he is less of a thief than mom - But it sounds like Mom is spreading the loot around to Dad so he will see it her way… I kind of doubt you are getting your money back. But you can learn from this. If you are old enough to have a job you can also have a bank account - but keep those documents or cards hidden from Mom. You could also get a modest safe, but be aware no safe is immune to being broken into given enough time and incentive. And the presence of a locked safe in your room will raise questions about what is in there.

Depending on the amount, file charges at the appropriate place. Do NOT let this go unpunished.

Don't allow her back in your house. She knows that money wasn't hers.