Originally Posted by SEA1K4EVR

Yes you can use your miles to book a seat in anyone's name. Won't be a problem to book one for your child even if on a separate record. Actually though in this case you would not have to book separately.. you can have one PNR for both people even if you're paying from separate mileage accounts as long as both passengers are on the exact same flights. However this can only be done on the phone and will likely require you to pay the phone booking fee. Personally I'd just do it online..there's really no major advantage to being on the same record... and certainly not any advantage worth paying for.