Hello Mr Maidlow I am also looking for a Mary Pearse, and noticed your posting.The name Saunders Hornbrook was so unusual I looked it up and have probably ruled it out as a connection, but I jotted down everything I could find for you.(You may have some of this already)
This is all off the Mormon search site, which has recorded hundreds of thousands of British church records.www.familysearch.org
Thomas Hornbrookmarried Prudence Saunders
They had several children.I found records for Prudence Hornbrook, b 1736, Patience Hornbrook, born 1738, and Jacob Hornbrook,(your relative, I assume) born 1730 in Plymouth Devon.
Jacob married Barbara (also listed as Barbry - no last name listed) and had several children.Found listings for Thomas Layd Hornbrookborn Feb 2, 1766 and Saunders Hornbrook (your relative) born Aug 6th, 1772.(This date could be off as there was a christening record a few years off)
Saunders Hornbrook married Mary Pearse (unfortunately not my Mary Pearse)July 8th, 1794 at St Stephens by Launceston, Cornwall.(I couldn't find any records for Mary Pearse with the birth date you listed - Nov 22, 1770.There was a christening record for Dec of that year which could be her, but since a lot of records are not recorded, there's no way to say, unless you know her parents' names and can confirm that this listing was her) Anyway, I found tons of records for offspring of Saunders and Mary.Here are a few in no particular order: - Anne Hornbrook born 22 April 1798 - Elizabeth Hornbrook born Nov 1799 - Saunders Hornbrook born 17 April 1795 - Mary Pearse Hornbrook born 14 August 1796 - John Hornbrook born 6 July 1801 - Sarah Hornbrook born 24 July 1805 - Thomas Hornbrook born 2 July 1807 (poor Mary Pearse - I hope that was all she had!) All children are listed as recorded atThe Abbey Chapel- Presbyterian, Tavistock Devon.
Hope this helps.Wish I could have found your Mary Pearse for you.I can tell I am not descended from her, (due to the name Hornbrook and the date is a little earlier than mine) but its possible I come from a sibling's line as Mary Pearse was such a common name and there is a connection with the area for my line.