Lovely name! I think you’re definitely on the right track with the slightly obscure “old lady” names. I think some from your list might almost be too mainstream, but they still sound nice. What about
Esther,
Pearl and
JudithEsther,
Agatha and
MabelEsther,
Violet and
TabithaEsther,
Sylvia and
ConstanceEsther,
Lydia and
OpalEsther,
Cecily and
HazelEsther,
Alice and Verbena