You've both narrowed down some great choices.
My top choices:
Clara has a few pronunciation variations in English: [Claire-rah], [Claire - ah] or [Cla-rah]. It doesn't bother me but some people may find it bothersome.
I think using Elisabeth as the middle name is more fitting because I usually just prefer using the exact name of the person you want to honor rather than a variant or alternative. Elisabeth is already a strong classic name too.
Cecilia may mean "blind" but it's mainly associated with St. Cecilia, the patron of music and musicians. It also has some mythology connection to Vulcan's son who founded an ancient Roman city. (Source: Wiki - Caecilia, BTN - Cecilia ) So it's not really a negative meaning name. Celia can also be a short form of Cecilia.
An alternative to Esther is Estelle or Stella.