According to the Tylenol website you can give an 11 yr. old of that weight 3 Jr Tylenol Tablets @ 160 mg each for a total of 480 mg. So I would think it would be alright. http://www.tylenol.com/children/subchild
Yes you can. I've been taking Tylenol since I was eleven and I didn't weigh much more than you and yes my mom gave it to me, but i only took like one at that age. It's ok but don't take more than one or two of them.