It's hard for me to imagine
Anna being dated, which mitigates the likely eventual datedness of the *bel part, so that wouldn't be a dealbreaker to me.
I kind of like
Susannah, but the problem is, I dislike it with any nickname.
And I do like
Annabel. It's ordinary looking but spunky and delicate, and the meaning's sweet.
It's a toss up if
Susannah is just
Susannah, but if not, then I prefer
Annabel.