I thought there was a huge missed opportunity with the death of Tessa. Earlier in the movie it’s mentioned that as a teenager Tessa attempted to burn down the house while her father and stepmother are inside.
Cut to the last act: Tessa standing in front of a fireplace wearing a flammable, loose-fitting caftan. Everything else in this movie was so predictable it seems only fitting Tessa would have died by accidentally stepping backwards and the edge of the caftan would have set aflame, or done so purposefully after seeing her scratched face and/or realizing she is a monster.
Since Julia is likely the only other person in the scene to know about Tessa’s past, it would have made for a more intriguing end.