Was the continuation of blood beyond forty days for the wife who had an IUD menstrual blood or istihadah (non-menstrual vaginal bleeding), and will she be considered in a state of istihadah in the coming months, such that she prays after 10 days?

What a wife sees after forty days is considered menses if it aligns with her usual period. Anything beyond her usual period is considered istihadah (non-menstrual bleeding). The minimum period of purity between two menstrual cycles is thirteen days. If she sees blood before the end of the purity period and she is in a state of istihadah, she should refer back to her previous usual period and perform what is required of one in istihadah. If the total duration of bleeding and intermittent purity does not exceed fifteen days, then all that she sees is considered menses. Yellowish and brownish discharges are considered menses if they occur during her usual period or are continuous with blood. She must make up for any prayers she missed if she abstained from them believing she was menstruating.