Its just a good thing to take Calcium and Magnesium anyway if your a lady...especially when your getting to menopause, or at menopause....I have to especially take it, because I take a med called Synthroid for my thyroid....I think Synthroid is hard on the bones.
I have been doing light weights for years....use to do heavier ones, but hurt my back...I use to teach aerobics and weights...Now my 13 year old daughter joins me for light weights...I once heard it isnt good to do weights until your fully grown,. BUT, I just give her very light weights...don't want to discourage her.