I have heard of someone whose doubled Matzeivo was inscribed with her name & praises when her husband died, so that when she dies, they just to add the death date.
That’s somewhat common as well. You often see that in cemeteries in New York where the second part of the stone is complete except for the date of death and age (if it was included on the stone).
One of the saddest things to see is a double stone with the second half not filled in and yet, you know, simply from the amount of time that has passed, that the second person is no longer alive. I’ve seen that a number of times as well.
The Wolf