Cable, housings and new rubber and it will be a solid ride.
As for the wife part. The stoker as the back seat person is called.
There are rules.
1 - Don't hit bumps.
2 - Do not complain if they seem to not be pedaling.
Lastly. The stages of tandem riding.
New tandem team.
Captain: Pedal!!!
Stoker: I am pedaling!!!
A bit more experienced tandem team.
Captain: Pedal harder!!!
Stoker: I am pedaling harder!!!
Seasoned tandem team.
Captain: You're doing great!
Stoker: I am pedaling you know!!!