They are buried in Evergreen Cemetery, right outside of the City of Salem.
On my last trip to Salem a few weeks ago, I was able to find Carl's obituary, with a picture, so do expect a post about this soon! Unfortunately I had no such luck with Bertha, nor did my helpful friends at the historical society, so I'm missing that reflection on how others remembered her. However, I do have her certificate of death. Again, post to come (I'm saying that a lot, aren't I? So much writing to do!)
There is a fourth child, Samuel Dennis Kilson, but he is buried at Beverly National Cemetery, also in Jersey. As to why he is there, but Carl is at Evergreen, when both are veterans, I do not know. Nor do I know why Bertha's headstone gives "W" as her middle initial. And her date of birth differs by a year from another record that I have for her. Not sure which one is correct, but in the long run, I think this is a small detail.
In any case, it was nice to be able to visit Carl and Bertha at their resting place, and was a good way to cap off a day of research.