That might be true though she never changed her position on things - hence the almost entirely British cast, films that remain largely true to the books (within the limits of crushing 700 pages into two and a bit hours) and so on.

Obviously it helps with negotiations when you're holding all the cards as she was - owned what looks like it will be the most valuable franchise in film history, undoubtedly had competitors queuing round the block, didn't need the money...