Hi,
The age on the 1911 is wrong - it is not unusual for an age to be incorrect on a census record. Ages, immigration dates, marriage dates, naturalization dates can all vary - the information is only as good as what the informant knows, it depends who gave the information to the enumerator. The father had lost his wife Kate when that 1911 census information was given, any one could have given information on the family, not necessarily the father. Look at all the other information - A UK BMD record showing Kate born Aston September 1902 (6d 378) - (that covers July/August/September 1902) The baptism record shows birth and baptism dates in August 1902. The immigration record gives her correct age. The marriage record quotes the correct parents. Due to privacy laws in Canada information is usually hard to come by but in your case you have been very fortunate that so much was found. Are you reading the links that we give ? The message board posts of a relative referring to Kathryn Ann Cockerill as his great-grandmother - although the thread was old (2003 if I remember correctly - try and post a message to see if you can make contact with the male poster)
Can't do any more to convince you this is the correct person. Ignore the age on the 1911 census -
Sandra