Hi P.,
I have two perspectives.
1. My father is very overweight and my mother never commented on how we children were. Her extreme was not to mention it at all if she was concerned. Now I have several sisters that are pretty overweight and I am slightly overweight. It is hard now to control it. However, although I am concerned I am not consumed.
2. My sister-in-law was constantly told what to eat, how to cut her hair, what not to eat, reminded about her weight and her mother always told her when she was gaining. She suffers with self-esteem all the time. She is consumed with keeping her weight down. She has her very healthy, very thin, very strong daughter counting calories and tracking salt, sugar, fat and carb intake.
There needs to be a happy medium. I think that if you make exercising and eating right a family activity and important to everyone, then your daughters will follow the example and maintain a happy and healthy lifestyle.
Also, remember that the high metabolism doesn't always last. So, keeping everyone moving and eating right will benefit all of you.
D.