I think Kim will be fine.
She played a lot last year. She's too good a player to need to play that much this year.
I doubt she will lose anything by cutting her schedule down. I would just fear for when she stops playing tennis, like when she's older could be a slight problem. But then I'm no doctor.
"Mentally prepare? Why? When you plan something it never works. It's simple: get in, drive car, see what happens."