How does a woman know if she is among those with a perpetual excuse due to vaginal discharge, and what is the approximate period between purification and prayer for her?

Continuous discharge is a permanent excuse, and the woman must perform ablution for every prayer and pray even if the discharge continues. If there is a period of cessation, she should wait, then perform ablution and pray, unless she fears the prayer time will expire, in which case she should pray. It is recommended to perform the prayer immediately after ablution. Also, one must avoid obsessive thoughts as long as they are not certain, based on the Prophet's (peace be upon him) saying: "He should not leave (the prayer) until he hears a sound or perceives a smell."