Well, as I said, I have scanned through LDS film 1298739 from St. Michael's in Belleville. I only went up to 1860. In the 1830's there were only Irish names. A few French names start getting mentioned about 1840.
On July 11, 1842, a Louis St. Louis married Susan Lezard. Louis Lezard was a witness. There is a baptism record for Mary Anne St. Louis on May 8, 1842, which says that she was two months old. The baptism record does not say illegitimate (which it does for other records) so either one of these dates is in error, or they had the quaint custom of not mentioning early births if a marriage was pending. Despite the fact that the second name does not match ( she was known as Mary Jane later) this is probably my great grandmother.
On Jan 24, 1841, there is a record of a baptism of an Agnes, illegitimate daughter to Andrew Longwell (sp) and Susan Lezare. Probably the same woman.
On July 26, 1844, John Harvey St. Louis was baptized, son of Lewis St. Louis and Susan Lezard.
In some places he is Louis, some places Lewis. She is usually Susan, but also Suzanne.
There is another St. Louis mentioned. On Feb. 12, 1845, there is a baptism of Mary, daughter of Joseph St. Louis and Margaret Brusette (sp). This could also be my great grandmother. If so, she would be only 15 when she married, but that was not unlikely in those years.
There were several Laurences or Larances mentioned, but it is hard to distinguish them from Irish families. However, one name, Felix Gaborie, does appear in several records. That is significant for me, because he shows up in the 1860's in Stoco, in land deals with my great grandfather. So these locations were clearly connected.
The given name Eli occurs in a couple of places, but no Eli St. Louis.