I just read a book called The Underground Girls of Kabul by Jenny Nordberg. The novel centers of the lives of several young girls in Afghanistan who live their lives as boys until they become teenagers. When these girls become teenagers they are required to get married and start families. The book focused on how poorly women in Afghanistan are treated and how equal rights for woman, even the right to choose who she wants to marry or when she wants to go is outlawed.
What if you had a character living under these conditions? What would her life be? Would she stay and endure it or would she try to escape it? Your story doesn’t have to center in Afghanistan, in fact you can create a world of your own. I know this prompt is different than my other prompts which verge of fantasy but sometimes I find centering stories on realistic situations makes them more compelling.