Look at your protagonist’s backstory.
Your characters’ histories offer rich veins of material. The more you know about your character, the more you have to write. For example, why does Molly want to get married when she’s 30? Because her sister got married at 30, and she’s always felt less loved than her sister? Because she promised an old friend she’d marry him on her 30th birthday if she didn’t have anyone else, and now he’s waiting for her, but she doesn’t really want to marry him? Because her mother has reserved a reception hall for Molly’s 30th birthday? Because she doesn’t think she’ll live to be 31? Recently I was reading Tracee de Hahn’s mystery novel Swiss Vendetta, which is about a woman trying to solve a murder during an epic Swiss snowstorm. Tracee’s protagonist is a young and inexperienced detective, and she’s struggling to project authority. But, about a third of the way through, she discovers something unsettling about her husband. It doesn’t necessarily relate to the case, and yet it bothers her, and offers a whole new and exciting vein of material to explore. What sorts of secrets is your protagonist concealing? What is she afraid of? What does she feel guilty about?