Like others have said, she looks fit and healthy.
Unfortunately, many women lose the "perfect 10" look when they drop curves in favor of the apparent endurance-runner look.
Endurance women rarely have good looking curves, it's difficult to maintain those fat deposits when you are into endurance athletics. Whether she is or not, I don't know. Also doesn't matter because I'll never get the chance to bang her, so really... what's the point? lol
She definitely has great muscle tone and definitely appears like she follows a good diet and lifestyle to trim back fatty layers and build up the lean muscle.
If you're skinny with little outward appearance of athleticism, you probably aren't perfectly healthy. If you're skinny with a lot of muscle tone and visible muscle mass, you might or might not be perfectly healthy, but you're probably right around an ideal level of health.
You have to care for your body to get the look she currently has, and you can't get that look without a lot of healthy effort and quality eating.
That doesn't mean I find her perfectly hot. I want to see fitness but still a little bit of softness to the flesh, and specifically I'd like to see some curves.