I think I have found this family in the 1881 British census: RG11 3099 23 Wellesbourne Hastings, Warwick, England: Robert Challoner valet domestic servant age 38 born Ormiston Scotland Louise Challoner wife age 37 born Lachoud (BS) Switzerland Agnes L. Challoner age 9 born London Edgware Road Robert L. Challoner age 8 born Wellesboune Warwick Cecile M. Challoner age 7 born Wellesbourne Warwick.
From the UK 1901 census index I think that Agnes and her mother were probably in Yardley Warwickshire in 1901.
Also by pure chance I yesterday saw a UK will index entry in 1922 for Louise Challoner of Indian Head Saskatchewan Canada (wife of Robert Challoner) died 16th August 1919 administration to Walter Shepherd the attorney of Agnes Louise Challoner.
Hope this helps.
I was interested in your message because 2 of our own Challoners emigrated to or near Indian Head in 1913 to go to the ranch of an Uncle Arnie. I don't yet know of a connection between your Challoners and ours, but do you know of any related Arnies at the time in Indian head?