My mom posted about 50 pictures of my on FB?

[Miyuki]

Usually it's the other way around--the kid's uploading photos and the parent wants to keep them from doing it.

I think the best way to handle the situation will probably be to sit down and have a serious conversation with her. Privacy is a real concern on Facebook; has your mother taken steps to secure her account and make the things she's posting friends-only? If not, try explaining to her that all of the photos she's uploaded to her account--and tagged you in--are visible to everyone, everywhere. While you can remove tags, it will not remove the photos from public view.

Encourage your mother to visit her account's privacy settings and customize them so she is not sharing her statuses, photos, and posts with everyone. If she makes them visible to only her friends, you will know exactly who's seeing them. I know it might not be as satisfying as deleting them from her account would be, but she's posting them because she's proud of you.

Here's the direct link to the FB privacy settings page: http://www.facebook.com/settings/?tab=privacy

Edit:

Regarding what "Bubba Freel" said about your face being your property... If your mom took the photos, she is the copyright holder. If you are a minor, she is legally able to sign model releases allowing your image to be published online or even sold for commercial use. Assuming that's true, she DOES have the legal right to post whatever photos of you she pleases as long as the subject matter is not illegal. Even if someone else took them, all she needs is the photographer's permission to post them without copyright infringement.