I think that while
Margot and
Pearl look nice together, I'd go with
Margo and Pearl--at least, I would if the pronunciation is MAR-go. (I think I'm alone in thinking that MAR-git is pretty.)
Do you want more names that mean the same thing? If you're going to be twinny like that, you might as well go the whole hog.
Margo Atarah and
Pearl StephanieMargo Deborah and
Pearl MelissaMargo Dawn and
Pearl AuroraMargo Natania and
Pearl TheodoraMargo Theodora and
Pearl DorothyMargo Blanche and
Pearl Alba or
Pearl Gwendolen
Array
"What are these parents thinking?...Let's name her Madison--she'll live in her own world: 16 square miles surrounded by reality." -- Susan Lampert Smith