You need to start early. Her father decided she was going to be a tennis star before she was born.
I still thinks she's on 'roids. I'm curious to see why anyone would disagree 
Why are you curious?, you haven't provided any evidence that she has used 'roid's'.
It's just ex post facto reasoning to suggest that a muscular physique and aggression are the consequence of steroid use. Anabolic steroids ape hormones naturally occuring in humans to varying degrees. The logical upshot of your position posits some standardized model of humanity in which excessive traits like muscularity simply cannot be accounted for by genetics alone.
The default position -unless their is evidence to the contrary, is that all athletes are considered to be playing by the rules.
