We don't yet know the full history behind Ann.

It's possible that she was married to a man named John Burt and in 1828, they had a son named Henry Theodore Burt. We know that Ann married Francis Knibbs in 1832, so if indeed Ann was previously married to John Burt, we can assume that he died at some time between 1828 and 1832.

The record of the marriage between Francis Knibbs and Ann Burt causes some confusion as it clearly identifies Francis Knibbs as a widower but shows Ann Burt as a spinster.

Another theory is of course that Ann was never married and her son Henry Theodore was born as a result of a previous relationship.