Every relationship is different. Some are good and some are not so good. Some are great and others are down right scary. It all comes down to whether you respect yourself and if the person you are with respects you.
The thing is most women go through several relationships in their life and each one will teach her something, Usually about herself. What she wants and what she doesn't want.
The best advice I can give, is as soon as you see it going bad, if it goes bad, get out. Don't waste time, energy or your heart on someone who will most likely never deserve it.