Here are my preferences

Charlotte May/Clare - Charlotte May - can be known as Charli or Lotti
Georgia May/Clare known as Georgie - Georiga May, Georgie is great nickname
Lily May - I think this might be a fairly common combo so I woul go with Lily Clare
Tessa Clare known as Tess - I prefer Tessa May, I think they just fit together better, no real reason, and Tess/Tessa is lovely, she may also get Tessie.

Gl!