A lot abusers wait or subtly engineer until it is very difficult for the woman to leave.

Having seen women get drawn into these relationships, I don't agree that there aren't signs until it is too late. The "subtle" signs are a period of boundary violating/disrespect/attempts to control that women put up with and disregard because of the ingrained behavior to be nice, put others needs first and fear of losing the relationship if they stand up for themselves. Having gone through this with a family member who was in an emotionally and financially abusive relationship/marriage the signs were there very early in the relationship, but she kept them a secret.

While they were dating, she would put aside her money for something else, only to find the envelope empty. He "needed" it for something, so he just took it without asking, but he'd never pay it back. When they got married she stupidly opened a joint account with him, only to see her paychecks get spent covering his business losses. He lost more money than she made over multiple years. He convinced her that as long as they stuck together he'd turn his business around and be making so much money. In the mean time, he didn't lift a finger as a parent (they each had a child from a previous relationship) and then had a baby with a birth defect that required special care, numerous medical appointments, and he did nothing. She didn't get a full night's sleep for almost 5 years because the baby's condition caused respiratory issues. He never woke up once in the middle of the night to care for his child. But by the time they were filing bankruptcy and lost their house to foreclosure, she couldn't imagine leaving him. Finally when the stress of caring for 3 children with no support, working, going back to school to get an advanced degree so she could make more money, and a second bankruptcy pushed her into an anxiety spiral, he couldn't cope because she was "crazy" so he cheated on her and then abandoned her.
Had she told him the first time he took her money without asking that she'd drop his ass if he ever did it again, she'd have saved herself a decade of financial ruin and the destruction of her mental health. She almost ended up in an inpatient psychiatric program. She has spent seven years putting her life back together. It is only because of very generous support from family members that she is back on her feet. But had she told him he couldn't take her money the first time he did it, he'd probably have bailed on her to find some other woman he could leach off of. Or of he kept doing it she should have dumped him. Something always seemed wrong, but she hid how bad things were for years.