Hello Joy,
While I have not researched the Castledawson C of I records I have researched the records of the Magherafelt Church of Ireland.
I have an entry for Margaret Lamon, daughter of James and Anne Lamon of Anaghmore, baptised at the Magherafelt COI on December 2, 1855.
This may be the last who married John Dougherty.
Ron Dale