I know and understand why if two people (spouses) have the same e-mail address, they must have two different passwords so the system can find the correct one when they log on. So, if one of them forgets their password, keys the email address and Clicks the "Forgot Password" link to retrieve a lost password, how will the system know which one to return, or will it always be the first one it comes to in the file? Thanks in advance.

It will automatically choose the first one. Person one could temporarily change his or her email address though, allowing person 2 to then use the lost password feature.