I had just come to that conclusion myself - I'll let you know in due course. I'm wondering if JK's second wife died (no record of that, yet) and he remarried a Mary Ann ...
As you say, living in the same house (if you look on Google street view, there's only one Victorian cottage in Eliot Bank), and then being buried in the same cemetery ... a bit of a coincidence!
Thanks for your help,
Sid