Peter and Janet traveled with six of their children from Campbeltown, Scotland in 1840 to New York on the ship "British Barque Tay" and went to live with her brother, Alexander in Cincinnati, Ohio, and then to Illinois in 1843, where they were part of the Scottish Settlement at Argyle. 
Janet (Brown) Ralston died from complications arising from the birth of Jane Ralston.
Janet died in August of 1845 after giving birth to Jane who only lived nine days.
Find A Grave: Memorial #53434543 Find A Grave, database and images (https://www.findagrave.com : accessed 18 July 2018), memorial page for Janet Brown Ralston (14 Aug 1802–1845), Find A Grave Memorial no. 53434543, citing Scottish Cemetery, Caledonia, Boone County, Illinois, USA ; Maintained by Harold R (contributor 46870133) .