How do you pronounce
Clementine? I say Cle-men-TEEN.
I think
Susannah Clementine is lovely,
Clementine is wonderful as a mn. (Avoids too many orange associations.)
Clemence is fine, but just doesn't compare to
Clementine, plus it's too similar to
Clement.
Susannah Lucie Clementine is good too, I don't think it's too much at all.