118lbs at 5'1 I would consider to be a very health sized individual. OP's mom might be coming from a good place but OP has a very happy and healthy BMI of 22.29. Now I am 5'7 and 141lbs and I certainly am in a healthy range as well with some muscle as well as some flab. My BMI is at 22.08. So I can assume as long as OP isn't a body builder she might have a similar body composition. It just sounds like her mom is a little bit on her high horse for eating healthy in her own way and wanting to push that lifestyle onto OP. Very likely for good reasons in her own mind. But OP is not at risk of being in an unhealthy weight and sounds like she is practicing good choices.