Irrelevant sex/gender information

So… took the cat to the vet for the first-time last week.  Happened to see a female vet.  I needed to make a follow-up appointment for Friday, and couldn’t do the time that she was on duty.  So I asked if we could see a different vet.  The receptionist said that there was another female vet available Friday evening, which we also couldn’t do.  She said there was yet another female vet available on Thursday, at another inconvenient time.  I was puzzled that she kept mentioning the femaleness of the vets, but then thought maybe some people prefer female vets (as I prefer female gynecologists, although the reasoning is a bit harder to discern).  So I explained that I didn’t mind a male vet.  She said “Oh, but all our vets are female. The male vet’s on holiday.”  Marilyn Frye, in “Sexism”, discusses the tendency to act as though sex/gender is relevant when it really isn’t.  This seems like a really striking example of that.