Teen Trends, and there were some Highschool Musical dolls out that used the same body. They are 17" dolls, and I know that Misty managed to put the head from a default 50cm on one. I also vaguely recall someone jointing the wrists on one of these.
These two are the cheapest auctions I could find, they are both for two dolls.
Teen Trends Auction.
Teen Trends Auction.