She had never received from her more than outward attention, nothing beyond the observances of complaisance; had never succeeded in any point which she wanted to carry, against previous inclination.
In that house Elizabeth must be first; and she was in the habit of such general observance as "Miss Elliot," that any particularity of attention seemed almost impossible.
…that nature, since he did not even know her to be in Bath, it immediately occurred, that something might be done in her favour by the influence of the woman he loved, and she had been hastily preparing to interest Anne’s feelings, as far as the observances due to Mr Elliot’s character would allow, when Anne’s refutation of the supposed engagement changed the face of everything; and while it took from her the new-formed hope of succeeding in the object of her first anxiety, left her at…
There are no more uses of "observance" in the book.
Show samples from other sources
As her release date neared, Vanessa got increasingly anxious, with a decided uptick in religious observance.
Piper Kerman -- Orange Is the New Black
"Religious observances shouldn’t be denied to anyone."