Is it healthy for a minor who weighs 143 pounds and is 5'5 to lose 25 pounds ?

Lina went in camping woods. while camping, she accidentally touched a strange planet. her hand immediately started itching, and her skin erupted in hives. after she gets home, her grandmother cooked some oatmeal, wrapped it in a cloth, and put it on lina affected hand. lina’s grandmother followed a traditional what remedy.