Did you asked Maramal about marriage before? I don't think potential spouses notice your amulet if you don't.
About the argonian's personal quest, A Few Words With You is one from a group of radiant quests, meaning if some in this page are active it's possible you have to clear it from your journal for Scouts-Many-Marshes to have a quest dialogue option.
Also, in the bug section I see :
Completing, or having this quest in the journal, can prevent Scouts-Many-Marshes from becoming eligible for marriage.