Likely either a Smith or Van Keuren couple, the album gives no clue to their identity.
Aunt Van Keuren
Noted as Van Keuren "Aunt", most likely by last owner of the album, Marguerite Van Keuren Clifton. Actual identity is unknown.
Van Keuren Cousins
Noted as Van Keuren cousins, probably by Marguerite Van Keuren Cliston, otherwise unnamed.