Hi Worried14,
Your weight sounds perfectly fine to me and i think the advice so far is good, tell your mum where to get off and eat if you are hungry!!
My Mum was always moaning about my weight and putting me on diets when i was younger and i'm not joking, i am obsessed with my weight now, feel guilty about eating anything that isn't a carrot stick and generally have no confidence in my body image at all- mostly because of her conditioning me to think i was fat.
Please don't let this happen to you, maybe you can compromise, there is no harm in eating healthily but at the end of the day, if you are hungry then you should eat.
Take care hun xx