If you enjoyed the "Monster's Bride" duet, you'll love this Christmas story as well. Just make sure you've read the duet first, because otherwise there will be a lot of characters to get to know all at once, without a lot of background. Also, for the full enjoyment, it would be awesome if you've also read the Neckromancer series, since Jaz and her men play a tiny part in this story as well, but that's not absolutely necessary.
This Christmas story has everything you might expect after reading Cressida's duet. It's a cute demon story, with a found family trope, and an even bigger focus on family with the whole Christmas theme. I loved watching all these characters interact with little Emma, and how they are settling in as parents in hell. This novella doesn't focus on big plot development, but it's a nice Christmas-themed story that fits perfectly with the holidays.