Well, clearly Emily and Allison are the main characters. They are the ones who are pregnant, so the story likely focuses on their experiences, emotions, and the changes in their lives.
There might also be other important characters. Their partners, if they are in the story, would be significant. They could be involved in the story by being there for the doctor's appointments, taking care of their pregnant partners, or having conversations about the future with the babies. And of course, their friends and family members who could add more depth to the story with their different reactions and interactions.
In some fanfictions, there could also be side characters like neighbors or colleagues. Neighbors might offer a helping hand or some friendly advice, and colleagues could be part of the work - life balance struggle that Emily and Allison face during their pregnancies.