This angel looking toward Heaven is holding an open book and a quill. The angel is clearly poised to write in the book. Here the angel is registering the name of the deceased into the Book of Life. In Judaism and Christianity, the names of the righteous were recorded in the Book of Life; they were assured entry into Heaven. The Book of Life is referenced many times in the Bible (King James Version), including Revelations, Chapter 12: “And I saw the dead, small and great, stand before God: and the books were opened: and another book was opened, which is the book of life: and the dead were judged out of those things which were written in the books, according to their works.”
The gravestone also carries an epitaph which expresses the belief that the recently deceased is going to meet her husband who has preceded her in death:
There’s a beautiful region above the skies,
And I long to reach its shore
For I know I shall find my treasure there
The loved one gone before.