Marking

Are you neutered? If not, suggest it to your mom... Intact pets are considerably more likely to mark than altered ones.

You could also try belly bands. It doesn't stop them from raising their legs but it does stop anything from getting on the furniture. Trust me, my mom's threatened me with them. I wasn't neutered until I was about 5 or 6 so it's hard to break a bad habit. It's harder to stop if they're neutered at an older age.