I believe John and Mary St. George in Milbury were
Jean Baptiste Laporte dit St George b. 13 Oct 1799 in St-Ours, Richelieu, Quebec, Canada and Marie Angelique Potvin dit Arpin 24 May 1807 in St-Ours, Richelieu, Quebec, Canada.
I have a public tree on Ancestry where you can see what I believe to be this family. This is gathered from personal research as well as with merging other trees on Ancestry. You can see it herehttp://trees.ancestry.com/tree/11432509/person/-465891358
I descend from Lewis St. George who I believe is one of their sons. I have not been able to trace John and Mary beyond the 1850 census. They don't show up in the 1855 Mass census althugh some of their children do. Some or all of this family moved to Putnam, CT around 1860 and some came back to MA, while others stayed in CT or RI.
There were a few St. George or Laporte families in the Worcester area. The name they used was "Laporte dit St. George", so you have to look for both surnames. As far as I can tell they all came from the St-Ours/Sorel, Richelieuarae of Quebec. Perhaps John and Mary moved back to Canada about the same time Oliver did. I found evidence of some of their children back in Richelieu in the 1861 Canada census. My guess is they did not return but some of their children did.
There is a death record for Oliver St. George, age 75, in Worcester on May 10, 1901 who lists his parents as Ignace St. George and Francoise Thibault. I found an Olivier St. George b. I think 23 Sept 1826 in Sorel to Hyacinthe St. George and Francoise Thibault. Ignace and Hyacinthe could be the same guy. I found a marriage record for Ignace Laporte and Francoise in Sorel in 1820.
Rosalie died in Worcester on July 12, 1908. Parent's names are not listed but maiden name of Tourville is. It was reported by an Ulric St. George.
I found the marriage record of Oliver St. George to Catherine Garsoe on Joan 6, 1848 in Cumberland, RI. They apparantly were living there at the time. Garsoe is probably a variation of Garceau