This is interesting…I’m following a thread on the APG mail list about German burial practices, burying more than one person in a grave with one headstone listing all those interred.
In my post about Paul Mayer, I mention the Two Mary’s. My 2nd-great-GF, Paul Mayer, was married twice before marrying my 2nd-great-GM. His first and second wives were both named Mary and both died a couple years after they married Paul. He buried them together under one headstone in the same cemetery where he is buried with my 2nd-great-GM. This was in the mid 1860s so I imagine it was a cost effective device for him, not to mention something he was probably familiar with as he immigrated from Germany.