Hera would be heartbroken. Sabine was like a daughter to her. Hera would likely become more protective of the remaining crew members. She might also be more hesitant in future missions, but she would also know that Sabine would have wanted them to keep fighting. So, she would try to balance her grief with the need to continue the Rebellion, and she would make sure Sabine's story and sacrifice were remembered among the Rebels.