My 24 year old dd has recently lost quite a bit of weight. She was overweight by about two stone at 12 stone at 5’4 she seemed to lose the weight very quickly. Now six months on she appears underweight. I borrowed her laptop and she had left up on the screen a Bmi calculator showing a bmi of 16.8 and weight of 7 stone. I believe by her appearance this is her weight at this time. Do I bring this up with her or wait until she talks to me?