Hi Wayne , everything that you have listed seems right . On the "Qualtrough" website Joseph Qualtrough married Olive Kermode 17/11/1885, their living range is shown as 1864-1890 amd 1861-1942. , on 1881 census Olive is with her parents John and Margaret in Lonan , you already have Robert Hudgeon also at Lonan.
Joseph and Olive's daughter Margaret Olive marries Henry Lane Turvill , on the "Q" website Margaret is shown as 1888-1954 (b 7/2/1888 Douglas). and Henry 1888-1951. M.O.Q appears to be the only child.
Can't find Joseph's burial date on Lawson's site.. You have Catherine's death 30/1/1900. Can't find Olives daeth on the IOM or England.
On the updated IGI site the marriage of Robert and Olive 28/4/1906 , shows them both widowed , his father William , her's John.Kermode.
Since Olive supposedly lived to 1942 , for Robert to marry the new Catherine in Canada , they must have divorced .............or were they not married ?
Could not find the deaths of Robert or the new Catherine in Canada on the new IGI (or a marriage between the two), but I did find the following deaths in Salmon Arm , British Columbia :

Margaret May Hoy , died 25/6/1974 , born Douglas IOM 21/8/1887 (?1890) , father Robert Edwin Hudgeon , mother MARGARET Clague

Charles Edwin Hudgeon , died 1/1/1968, Born IOM 12/3/1893 , aged 74 , Father Robert Hudgeon , mother Katherine Clague.

So it is possible all the family moved from Alberta to British Columbia , as it seems that the two deaths above are absolutely the family you are listing .

There are quite a few people who log onto this site who have a lot of infomation on the Clague and Qualtrough families , also a lot of Hudgeons anglicised their name to Hudson ,although the two Canadian deaths have not.

Hope this helps
David Dwyer
Sydney, Australia