Annabel didn't burn Annabel, because the doll is just a carrier, and Annabel can be possessed by people. So in the second movie, Annabel was possessed by Janice, an orphanage girl, and was finally adopted by a couple. In other words, Annabel can be possessed by other dolls or humans as long as her soul is immortal.

Annabel's plot summary

Annabel is a beautiful and rare antique doll, which is a gift from John Formay to his future wife Mia annabella Wallis. But Mia's love for Annabel didn't last long. On a terrible night, their home was violently invaded by a cult. However, the pagans left behind not only blood and terror, but also introduced an evil spirit to Annabel.