Como não foi imediato, parece que não foi um encantamento.
In most fairy tales, "True Love" can not be an enchantment, and "True Love's Kiss" would never work under a spell. It must be that Maleficent grew to truly love Aurora in her heart, otherwise the spell could not have been broken. It is also a better character arc, from a story-telling standpoint, to believe that Aurora's goodness rekindled the goodness that was buried in Maleficent.