I did find some footage of the Stewart's "dunk," which was no dunk at all. She does seem to be pretty slight of frame so I can see the point of the other poster's note that she would probably not match up with Griner until she can put on some lower body strength.
In the other footage that I saw, I didn't see her make a shot other than shots within about 5 feet of the basket, and she actually missed quite a few of those.
I'm not sold yet as I saw Griner play in high school and she was much more impressive. I am not sure that Stewart has the foot speed to play the 4 in college. I have not doubt that she will have an impact with her length, and she will undoubtedly develop under Geno's system. But comparing footage of EDD and Stewart coming out of high school, EDD was a much more developed player. I think that Stewart will be about two years from making a major impact, but she will certainly impact the game.
Stewart does appear to have a sweet stroke from three-point range. Surprisingly, Griner also has a pretty sweet stroke from 3 range, although nobody gets to see it unless you watch Baylor in warm-ups. I've watched her shoot in warm-ups and the percentage that she makes is pretty impressive. But like Griner, I am not sure that you want a player of that height and length standing around the three point line.