It would be in character if she was sincere, but also in character if she was acting, considering she just called out Madoka for doing it in the scene prior.
Good one author, I feel played.
On the flip side, the existence of the dream machine as perfect as the one in the story and Maki's ability to simply alter it to its present capabilities felt like a cop-in to the conflict, so a cop-out doesn't seem like much of a problem.