Do you want Maggie to play fetch for you or for her? If she doesn't like the game but want her to learn you can teach it but be mindful she may never learn to love it. If she is like my Pyr (not a fetch dog) it's fun to chase and we just use the ball as kick toy. At least I'm the one burning calories.
I read a book that talked about backwards chaining. Basically, you teach the process of fetch from back to front.
For example: Fetch = Throw ball >> dog chases >> retrieves >> releases ball back to you. So first you teach releasing the ball. This is the only part of the process that gets a reward. So as your dog is getting rewarded for just taking and giving you back the ball you start to add distance. Again, if she likes the reward of giving this ball back to you enough your dog may start to like the game enough to do it for free.
Noah is not very enthusiastic about this at all. I'm lucky if I can get him to do it once. Harley, is showing more interest in the game and maybe one day I will have the only frisbee catching great pyrenees in the world! It might be easier to teach this to a chicken but I have to try!