As a runner, I hate the bad for you excuse.  It is always from some lazy fuck up who tries jogging once and twists a joint wrong since they haven't developed any type of coordination and lateral strength.  What do you think agility training is for?  And wolf's law clearly states that impact will develop stronger bones in the direction of impact.  Bones are living things as well, they do repair and grow. A lot of women don't lift heavy for fear of looking masculine. But, she should be doing a lot better, especially if she's a trainer.  Ever seen a lady go from flat ass to curvy ass?  Booty gains, bruh.