"He [Sam Walton] left his ownership in Wal-Mart to his wife and their children: S. Robson "Rob" Walton, John T. Walton, Jim Walton, and Alice Walton. Rob Walton succeeded his father as the Chairman of the Board of Wal-Mart, and John was a director until his death in a 2005 plane crash. The others are not directly involved in the company (except through their voting power as shareholders). "
source: http://askville.amazon.com/owns-Wal-Mart/AnswerViewer.do?requestId=366395
i couldn't find any evidence online that walmart owns either joann's or michael's. that doesn't mean they don't. it just means i couldn't find any proof they do.