I have a plan to fly with my kid to my parents (CDG-FRA) for the sake of example), leave the kid there for a couple of weeks and then let my wife do the same flight and bring the kid back.
If I were to be on both flights, that wouldn't be a problem: I could book a round trip for myself and the kid for the whole duration of the holyday (CDG to FRA on day D and return on day D+14), and then just book a round trip for myself in the opposite direction (FRA to CDG on D+1 and return on D+13). However, I will be busy on D+13, so I wonder if my wife could fly instead, without booking super-expensive one-way tickets for every flight.
What options do I have?
EDIT: the airline in question is Lufthansa, and my kid is 5 y.o. (so he needs a child ticket).