We're looking to use our United points for a series of flights on Lufthansa. All 4 flights would be operated by Lufthansa. When I go to do the booking on United's website,it says that seat selection will occur during check-in. We're a family of 4, with 2 small kids, so we would need to sit together and I'd want to pick our seats long before check-in.

Can you really not pick your seats on Lufthansa flights booked with United points until check-in? Would I be able to call Lufthansa to get seats once we've been ticketed? Any help would be appreciated!