There is a tree on Ancestry which has John & Janet's marriage being Mar 14 1866. First child was Gilbert Jardine born 31 Oct 1867 Howick Tp., Huron Co., died 1945 (my note - think he moved to Manitoba); second child, Mary Jane Jardine born 29 Jan 1869 Howick Tp., died 1952.
The 1881 Census shows this is true:
1881 Ontario Census 175 - Huron North County, A3 - Howick Tp.
John Jardin 44 b. England married Farmer
Janet Jardin 35 b. Ontario married
Gilbert Jardin 13 b. Ontario
Mary J. Jardin 11 b. Ontario
Philip J. Jardin 9 b. Ontario
Janet Jardin 6 b. Ontario
Caroline Jardin 4 b. Ontario
John S. Jardin 2 b. Ontario
Name: Mary Jane Jardine
Event Type: Birth
Event Date: 29 Sep 1869
Event Place: Huron, Ontario, Canada
Gender: Female
Father's Name: John Jardine
Mother's Name: Jennet Mcintosh
Name: William Gamble
Event Type: Marriage
Event Date: 23 Jan 1901
Event Place: Howick, Huron, Ontario, Canada
Age: 31
Birth Year (Estimated): 1870
Father's Name: James Gamble
Mother's Name: Margaret J Hicks
Spouse's Name: Mary Jane Jardine
Spouse's Age: 31
Spouse's Birth Year (Estimated): 1870
Spouse's Father's Name: John Jardine
Spouse's Mother's Name: Janet Mcintosh
Gilbert Jardine was in Manitoba by the 1891 Census.
1921 Manitoba Census Portage La Prairie
Gilbert Jardine 52 b. Ontario
Lena Rose Jardine 38 b. Ontario
Lena Jardine 13 b. Manitoba
Ellen Caroline Jardine 7 b. Manitoba
Norman L Byron Jardine 1 b. Manitoba
Caroline Boughen 78 b. England mother-in-law Widowed
Mary Edith Taylor 55 b. England Friend
http://newspaperarchive.com/ca/manitoba/dauphin/dauphin-hera...Wednesday, April 19, 1972 THE DAUPHIN HERALD OBITUARIES MRS. ROSE JARDINE- Mrs. Lena Rose Jardine, age 89 years, one of Dauphin’s pioneer settlers, died Monday, April 10. Lena Rose Boughen was born at Port Hope, Ont., & came west with her parents to near Dauphin in 1890 when she was a child of 8 years. In 1904 she married Gilbert Jardine and farmed in the Valley River district for 40 years. Since the death of her husband in (Jan 31) 1945, she had resided in rural Dauphin & in the Eclipse District for 18 years, coming to town in 1971. She was a member of the Dauphin Pioneers Association. Surviving are three daughters, Mrs. A.O. Richmond (Mary of Winnipeg, Mrs. J.J. Murray (Ellen) of Dauphin, Mrs. J. Bisch (Thelma) of Hamilton, Ont. There are five grandchildren and two gr-grandchildren. Mrs. Jardine was predeceased by a son Bryron in 1966, five brothers, William, Edmund, Benjamin, Arthur and Thomas.