I have to agree with alot of others here about doing direct deposit if its available. my mom used to do that with my little brother and take his checks and cash them. So I helped him get another account setup and he got direct deposit. End of problem.

Not cool for your mom to do that! Maybe try auto deposit?

Usually when checks are cashed they ask for ID...so how does she manage to do that?

Let the bank know what is going on. they should be able to put a note on your account to make tellers aware of a possible "fraud".

Just use something like a smiley face for the bank. When I worked at a bank some did that for their signature and it was a great idea...dead giveaway if she tried to sign your name.

Let her do it and then sue her for fraud

Scrolled through looking for the obligatory and stupid "your mother raised you so she is entitled to steal from you and ruin your life" comment, didn't find it, faith in humanity + 1

This does not seem foolproof.

Just to touch on a subject here, OP could very well be a minor. At that point, parents can take money regardless.

Add a shape to your signature. When I sign for banks, I might use a heart or a star vs a normal dot for my other signatures.