Class of '57 characters

[Fedide]

I am looking at the Class of '57 game as this is for a conservative church group.

The group will not all be couples. If I assign the first five couples/ten people (the minimum required characters) can the remaining ten characters be assigned as singles, or must they be couples for the game to work? ( I noticed the character list had them as couples.) Or..would it be better to use the extra characters packet for any singles? I probably will not have an even male/female ratio. Thanks!