I think it's somewhere in the middle. Yes, she will develop physically, and her first year on tour was always going to be tough. Equally though, the top players have a mental resilience which she appears to lack at present. Look at Rafa winning the French with basically half a foot, and his hands taped. Emma needs a decent sports psychologist, and to decide whether she's willing and able to make the sacrifices required of the genuine greats.
That said, tennis is an interesting sport in terms of just how mental it is. I've played to a reasonable level, and more than any other sport the smallest niggle can completely throw your game. If I play the day after a long run on slightly heavy legs for example, my serve is completely out of whack presumably because I don't jump as high or fast and the timing is all off. If I play with a sore finger my groundstrokes completely go. Small injuries don't affect other sports in the same way, in my experience.
Again, the top players deal with this kind of issue, and Emma needs to work out how to do so, but she's young, inexperienced, hasn't dealt with much adversity until this year, and I hope will learn and develop.
