It is all a small-scale tennis tournament organized by private persons, not to compare with the tournament at the Monte Carlo Country Club (which is played this week by the way) attended by legends as Roger Federer and Rafael Nadal. I think the Princess looked nice, just private.
I agree about the legs. These look pretty pale for someone living at the sunny French Rivièra and also skinny, the legs of someone on a too low calories diet, causing a decrease in musculature. Professional swimmers have used their body to intensive trainings and work outs, for years and years, often already in childhood. The Princess has ended her career. Her body never gets the same, almost daily, "workload" to burn a massive amount of calories. This means that probably the Princess has starved/is starving herself to compensate the loss of training intensity with a lower intake of calories. Not very smart. Often the body "eats" the musculature (by lack of body reserves as fat) causing a very skinny look. Of course that last part is purely for my own account. I am just guessing on base of what I see.