This was on a blog last year tho’ not fleshed out like this. The suggestion was made that Stanley Ann actually was living in Seattle and went up to Canada to give birth (don’t remember the reason given for why she would want to do this.)
Don’t have the reference but IIRC the theory was her folks sent her to an unwed home in Canada to give birth and put baby up for adoption. After, Stanley would go to U of Wash as she had wanted to do. So goes the theory that Stanley changed her mind and shows up with a pink newborn and unknowledgable about diapering and such when her friend meets her.
Perhaps she was supposed to give the baby up for adoption, but then, being quite headstrong, reneged on the agreement with her parents to do so.