This is a sentence from another evening at the club

the spectres of the eucalyptus trees ranged along the garden fence rocked before her gaze, with white egrets slumbering on their high branches like huge white flowers among the thin leaves

the author most likely compares the eucalyptus trees to spectres to suggest

the woman is troubled by something
a sense of mystery about the woman (my guess is this)
the woman is in imminent danger
the fragile state of the woman's health

Initially, it may seem like the author used spectres for her description of the trees in the setting in order to create a mysterious mood in the story. However, by reading the story, you can notice that the protagonist is sitting down remembering and reflecting, without further suggestions of mystery. On the other hand, what the protagonist is pondering on and the emotions she reveals, along with the setting, express the fact that she is troubled by losing her wedding ring. Therefore, your best answer is the woman is troubled by something.

The answer to your question appears to be: hardworking