What was her motive?
The child WAS her grandson. Her flesh and blood. Were he born in Canada by the idiotic action's of her daughter, she would have a powerful motive to fabricate American citizenship for him. In 1961, American citizenship was the envy of the world. A Grandmother would be remiss in not securing it for her Grandchild.
The probability that Stanley Ann Dunham was in the Upper West part of Washington state prior to his birth makes more sense than that she flew there on an impulse shortly after his birth. In 1960, it was quite common for pregnant your women to be sent to live with a distant relative to avoid embarrassing the family. The incentive for this might be even stronger for a bi-racial child in 1961. In many states that was a felony in and of itself at that time. She did have an Aunt Eleanor that lived in Washington, though it hasn't been nailed down exactly where she was in 1961. Aunt Eleanor is listed as living in both Blaine and Bellingham Washington, so a trip to a Canadian hospital for free medical care is not out of the question. Aunt Eleanor was definitely living in Newfoundland Canada in 1959, based on the grave markers of her children.
Examine these links.
http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=34618044
http://radaris.com/p/Eleanor/Berkebile/ (Look for Eleanor *B* Berkebile)
Note the proximity of Blaine and Bellingham to White Rock Canada?
This theory actually makes more sense than what we've been told. Another piece of information that reinforces this theory is that Madelyn Dunham's co-workers claim that she never told them she had a grandson. This implies that she was ashamed of him at first.