Is it obligatory for a girl to specialize in Islamic studies instead of literary studies, especially with her talent for writing stories, due to her feeling that writing Islamic articles takes precedence over fictional novels?

A Muslim can serve his religion and call to Allah from any place, just as Yusuf (peace be upon him) did in prison. Writing impactful stories is a beneficial means, and there is no contradiction between it and Islamic articles. When writing about religious rulings, one must be meticulous by presenting what has been written to a scholar firmly grounded in knowledge.