Yes, she can be one of the greats. The physical abilities are there, the length and range, and the power is just beginning to show. According to her, she's not even very strong in the gym, can't even lift two plates. Imagine how much better her serve becomes when she gets those two plates up.
Let us wish she stays injury free, nothing really serious.
She can still improve her game. Most experts were amazed that she reached the QF of the French without much spin on her balls, so again, imagine what if...
And she's fairly ambidexterous, too. Not that it's a big thing, but who knows when that "secret" wicked left handed serve comes in handy?
The changes will come, of course. Let us just wish that whatever those changes are, that they don't undermine her focus and her game. She seems to be capable of shutting out the rest of the world while she's on court, so that shouldn't be much of a problem.
Also, neither she nor we should put too much pressure on her. She doesn't have to win the next US Open, although that would be nice, too. (I read and read Boris Becker's article and can't help but say he's right. Maria should take her time. She's entitled a day off, even is she's Wimbledon champion.) We are, after all, just fans. We came to her, she did not ask us to come. She has EVERY right to throw her life or career away, if that's what she wishes, and there's nothing that we, her parents or advisers can do about it. But again, from what I've seen from this young woman, the chance of that happening is as remote as the South Pole. She's special, especially on the mental aspect.
She can be one of the greats. in two years she may already be.
OK, I'm getting off the soapbox now.