That more of an old fashioned way of referring to one’s wife.

Better that Biden being confused about his wife and sister while they were standing next to each other.

I used to work in a jewelry store. An old man and old woman came one one day and he kept picking things out and saying things like "Mother, what do you think of this?"

So I assumed it was his mother and I asked him if it was his mom's birthday or something like that he he got really offended. He said something like "does my wife look that old to you? old enough to be my mother?"

It was really weird and they didn't buy anything after wasting a bunch of our time.