In 1881, Henry G. Petch (31) & Sarah L. Petch (18) and young daughter Louisa M. Petch (7 months) were living in Chinguacousy, Peel County.The family is listed as Methodist.
In 1871, Henery G Petch (21), s/o James G and Sarah Petch was living in Chinguacousy, Peel County.The Petch family was listed as C of E (Church of England=Anglican).
In 1871 there is a Sarah Jones, age 4, daughter of George & Louisa (mis-transcribed by Ancestry as Lavina) Jones, living in Brampton, Peel County in 1871.This Sarah Jones had a twin sister Matilda.Brampton is 10 km (6 miles) from Chinguacousy.In 1881, Sarah is listed with her family, but crossed off.
It is likely that this is the family of your Sarah Louisa Petch (nee Jones) and it is likely that your Louisa Matilda Petch (age 7 months in 1881) was named for her mother’s mother Louisa and her mother’s twin sister Matilda.
In 1871 the George Jones family was listed as Ch. of England (Anglican).It is likely that the marriage of Sarah Jones and Henry Petch, about 1879-1880, is recorded in the marriage registers of the Anglican church in Peel County.Baptism, marriage and burial records for Peel County (including Chinguacousy), are kept by the Anglican Church of Canada, Diocese of Toronto, Archives.Even if the marriage was not registered, it should be recorded in the parish registers.
By 1891 George (63) and Louisa (62) Jones were living in Derby Township, Grey North, Ontario.Many of their children were married in Owen Sound in the 1880s.Marriage registrations list Louisa’s maiden name as Price.
George Jones (72) died in Derby, Grey County in 1900.It is likely Louisa died in nearby Keppel, Grey County in 1922.
I have had great luck in getting family obits from the Bruce & Grey Branch of the Ontario Genealogical Society, Surname Collection.You can ask for just the surname you are interested in.