I can see how her legs in some shots (particularly the video) look a bit extreme, but her legs (and stomach) seem pretty consistent with a lot of ballet dancers/rhythmic gymnasts due to the combination of lots of muscle and low body fat. I also think that video makes them look even more vascular due to the black and white highlights and shadows, and the obvious hard flexing, as her leg that she’s not moving looks more normal. Her legs in older pictures also look like they’ve always had a lot of muscle on the thighs (like a lot of dancers) and the loss of body fat makes them plus the veins show up a lot. I don’t think her body is attainable or usual for the average person, but the way it looks could be the combination of her body type and type of/amount of dance she does. In terms of her health based off of that, I obviously do not personally know, so I can’t make any comments on that.