Originally Posted by LufthansaGermanAirlines

Hello cas_de,
If you have a code-share flight on your booking, it may indeed not be possible to reserve a seat or other special services due to technical difficulties. If my colleagues from the Service Center are unable to make a seat reservation, please try reserving your seat during check-in. Should you not be able to find seats together at the online check-in, I recommend you to contact my colleagues at the airport, or also my crew colleagues once you have boarded; I'm sure they will do their best to assist you.
I have forwarded your question regarding child meals reservation and will get back to you as soon as I receive an answer.
Kind regards,
Heloisa