I think this represents a really good (I might even say fantastic) start for Mary.
To beat Ai in straight sets, having not completed a competitive match in how long, and then to push Myskina who is on one of her hot streaks means that Mary Means Business imo... and that's good to see.
"Mentally prepare? Why? When you plan something it never works. It's simple: get in, drive car, see what happens."