It's part 86 of this series and I've finally found a gravestone that explicitly mentions heaven. I thought it would never happen. One other uses the adjective "heavenly," but that's as close as I've gotten.
The Remains of
Mrs. Elizabeth Fernald
Mr. Nathanl. W. Fernald, & daughter of
Capt. Nathanl. Melcher,
who resigned this life,
in calm and humble hope of heaven
October 5th. 1809, Aged 36 Years.
Kind husband, children, parents, friends,
When here you rest your eye;
Or pensive tread this hallow'd ground,
Remember, you must die.
Elizabeth Fernald, Portsmouth, NH, 1809