It may be too late, but I'd hold off on potting up the keikis and leave them on the mother plant longer. The stems are nice and green and hold water and nutrients for the keikis. I don't see any signs of rot or infection you'd want to protect the kiekis from and would suggest you try to be patient until their roots are longer. I've got an Epidendrum that grows much like that, the older stems keep getting black spots and losing their leaves while throwing keikis everywhere. When I remember to spray it for fungal infection regularly, it shapes up pretty well, it grows like weed though. Anyway, its going to be hard to keep those keikis alive without more roots, while they are doing great on the mother plant. Good luck either way!