Curious to see her out this time of year. Normally they fly mid- to late spring. Maybe early stages of "zombie-fungus" infection, and I'm not just saying that because it's Halloween.

Or when you say other smaller ones, you mean she was exposed in a nest with workers? In that case, most likely their mother, who dropped her wings long before any of the workers existed, just after her spring mating flight this or in an earlier year. Yes, they do live many years.

Moved from ID Request.