The transcription for the gs for Rice BAKER, Hugh BAKER and Hanna BAKER LEWIS is on the Elgin OGS web site at: -
http://www.elginogs.ca/Home/ancestor-indexes/gravestones/st-...The death registration for Hannah's son Edward A. LEWIS confirms that his mother was Hannah BAKER. and footstone for Rice gives him as "Uncle Rice" so good bet that at least Rice and Hannah were siblings.
FamilySearch records give that Rice BAKER was born 8 April 1810 Holy Trinity, Shaftesbury, Dorset, England, son of Stephen BAKER and Maria. Hugh BAKER was born at same location 28 Oct 1813 same parents. A Hannah BAKER was born to parents of same name. Christening date was 25 May 1825 and place was Semley, Wiltshire, England.
See Elgin OGS lookup policy for checking for obits in the St. Thomas newspapers at:
http://www.elginogs.ca/Home/lookup-policy