Yes, I agree that Nadia looks super fit.
She is great to watch when playing like this, isn't she? 6 years on from her prime and she is still one of the best 16 players in the world on a regular basis.
As for Maria, she could beat her. She has the serve and the groundies and if Maria has one of those off days where she's blasting balls into the stands and yipping then Nadia could finally beat her.