Using Facebook settings, you can change your relationship status (Single, Engaged, Married, etc.) To add or edit your relationship status follow the steps below
Change Facebook relationship status
From your News Feed, click your name. Click “About“.
Then click Family and Relationships in the left column.
Choose your relationship status from the dropdown menu. Depending on your status, you may also have the option to add the name of the person you’re in a relationship with and your anniversary.
You can also add your relationship status as a life event on your profile. That is all!