When a tiny child died, the cost of a funeral was beyond the pocket of a poor family, so an arrangement was made to bury the infant at the same time as an adult’s funeral. In front of the glass hearse there was a little glass compartment running the width of the hearse, and the little coffin was placed there, and so buried in the adult’s grave....None of us attended the funeral, but I remember we had black sashes to wear on our Sunday dresses.
After a lot of searching, I came up with nothing further on this burial practice. I believe it is a form of tandem burial but this search term revealed no further details on the above (but it did turn up a lot on an 'historical' Irish hospital practice which came to light a few years back, concerning the burial of un-baptized babies in the coffins of unrelated adults). I may, of course, have been using the wrong search term.
Searching Victorian / Edwardian funeral practices also turned up nothing, though I did learn a lot about burial clubs. I also tried searching Florence Hannah Warn but again drew a blank.
It seems strange that I've turned up no other information so I'm wondering just how widespread burying a child in the grave of an unrelated adult was.
Was this just an Edwardian practice, or does it date back further than that? Is there any archaeological evidence, for example, of this happening in earlier times? When did it die out, or was it made illegal?
EDIT The example here seems to be different from a 'common burial' as suggested by Boaz's comment. I may be reading too much into the passage cited, but it seems this was an individual adult's funeral - a hearse has been paid for (and a glass one at that - not cheap?). This raises the additional question as to whether the child's name appeared on a gravestone - maybe not, as the family did not attend the funeral.