My mom might see my questions...what to do?

First of all you should go into your settings on here and make it so no on can see your questions. There's nothing you can really do about the questions she already saw. However as horrible as it sounds but if your grandma tells your mom about them.....I would say I have no clue what she's talking about. If your grandmas anything like mine then she doesn't know much about the internet and technology and would probably forget all about them. If I were you I would create a separate yahoo account just to use on yahoo answers from now on with a screen name that's not your own name. That way you can still ask questions but no one will know it's you. :-D