The second was a much tougher match. The message was the same. KE, being significantly weaker, tried to stay at the front. Even on long serves - goal is to hit is such that she can go back up to the front. That's not to say that she should always stay there - only long enough until she learns how to hit it with more power from further back.
Mixed doubles implies that there's a player who is significantly weaker.
Otherwise, they would be playing doubles, irrespective of gender.