I think
Arabella is pretty, but it's too fussy for me. I think it goes nicely with your other names, but it is a step further. It's less sturdy than your other names (except perhaps
Edwina).
I don't know about popularity. I've only known of one, a few months younger than
John. But a little girl in Florida doesn't shed much light on what your daughter's experience would be.
Personally I prefer
Daphne. I think it's spunkier and has a more versatile vibe than the fussy
Arabella.
Daphne Hilda Arabella is pretty lovely though :)
~Anna~