Having trouble with parent, please help!?

Okay did you mean 115? or 215? If it is 115, you are already severly underweight. You're BMI is around 15.6, and for normal weight you need to be between 18.5–24.9 which would put you at 135 to 180 lbs. I think you should concentrate on gaining weight and have some one those strudels. If you meant 215, then 30lb weight loss would be reasonable. Just try to explain that her habits are effecting you and your health. Tell her healthy foods that you would like to have instead of the junk food, and that you do not want to have to wait until you are 18 to live a healthy productive lifestyle.