It's the "Misty (Bring Her Back) Club RPG!"
Anyway, welcome to our newest member (and by the by, we're no longer keeping track of who has which Pokemon). Congrats on a nice pic, ML17.
Finally, the reason Misty doesn't seem to get much stronger is because we see her battle so rarely. She was strong to start, but when next we see her *really* battle, she's probably skipped up to another plateau of strength and it's hard to see the difference, as we didn't see much of the training we did to accomplish that new level. I doubt she's anywhere near he skill limit, though. Besides, the animators want to make Ash look better, in my opinion, and thus they occasionally make Misty seem weaker than she is.