I say, and with God's help: The woman experiencing irregular bleeding has an excuse, so her prayers are valid even with the discharge of impurity during the time. One ablution is sufficient for each prayer time, and her ablution is invalidated upon the end of the time. She must remove the impurity from herself during the prayer if there is no hardship in doing so; if there is hardship and necessity, then praying with it is permissible. And God knows best.