She wants Will to be dominant only when it suits her...meaning she wants to maintain control, even over the way he's allowed to be a man.
She's trying to be strong and independent while pretending to be traditional and submissive. It never works, true colors come out.
Telling a man to man-up is just a shaming technique. She's not encouraging him to be more of her version of manhood, she's nagging him - even mocking him. Despite what she claims, she doesn't want a traditional marriage. And telling Cal that she'd gladly be barefoot and pregnant in the kitchen was a complete lie. I'm sure she wants kids, but Jas would freak out if Will told her to go make him a sandwich.