I have no children, and I've never undergone IVF, so I can't help you there.
Your combinations are all quite nice, my favourites are:
Lillian &
AudreyLillian &
AnnaLillian &
Grace Lillian &
Sophia
Lillian &
DavidLillian &
Nathaniel (
Nate)
Lillian &
Samuel (
Sammy,
Sam)
Lillian &
Simon
Jacob &
DavidNathaniel &
David (
Nate)
Samuel &
David (
Sam)