Is a girl considered sinful for not performing ghusl and praying the obligatory prayers on the sixth day of her menstruation if she doubts her purity after the cessation of blood in the morning and fears the return of blood on the seventh day?

A woman recognizes purity by two signs: the dryness of the spot, meaning she finds no trace of blood even if she inserts a tissue, or the emission of the white discharge (white fluid). If a woman's habit is the dryness of the spot, then she must perform ghusl and pray as soon as she sees it. But if her habit is to see the white discharge, she should not hasten until she sees it, unless there is complete dryness and purity of the spot. When in doubt about purity, the default is the continuation of menstruation.