Sam could develop by becoming more in touch with his emotions. Usually, he's tough on the job, but with Jules pregnant, he might show a softer side more often. He could learn to communicate his fears and hopes for the future better. Jules, on the other hand, might become more assertive. She's always been strong, but now she has to advocate for herself and the baby. For example, she might be more firm about Sam's safety on the job.
Sam's character might develop in terms of his perspective on life. The idea of becoming a father could make him reevaluate his priorities. He might start thinking about leaving the more dangerous aspects of his job in the future. Jules could develop a deeper bond with the female members of the Flashpoint team. They could support her through the pregnancy, and she could learn from their experiences. This could also make her more of a team player in a different way, as she shares her journey with them and they all grow together.