Actually, actors
Emily Blunt and
John Krasinski have two daughters named
Hazel and
Violet! I wonder if they'd consider
Ruby for their next daughter (if they'll have one, of course).
I don't mind if siblings' names follow a certain theme (in
Hazel,
Violet and
Ruby's case that would be vintage, color and nature). It's more distracting if the names look/sound too similar, for example
Emma,
Emily and
Emmeline.
As for the question about
Ruby Clementine, I prefer
Clementine Ruby.