Does it say anywhere where she got the name and possible birth certificate (e.g. from a deceased child)? Apologies if I missed it. The significance of the name "Diedra Grace" is certainly interesting, and using an alternative spelling of the first name probably stuck out a bit. Does anyone understand the Gideon mention? Just curious- it sounds like she might have eventually found religion?
Nothing I've read or come across says how she assumed the new identity as Glabus. However, I am unsure if Kinne actually stole and used another person's identity for a couple of reasons: one is the Diedra Glabus id has a birthdate of 11/30/1940; Sharon Hall Kinne had a birthdate of 11/30/1939. Secondly, both IDs have Independence, Missouri as her place of birth. While having her new ID align with her true place of origin probably made keeping her story straight easier, the nearly identical dates of birth are strange, with Glabus being one year younger exactly.
I'm going to conjecture here, partly based on what I just mentioned as well as my own work experience dealing with identity documents like birth, death certs, and potential fraud. Kinne, I think, actually "mutated" her own identity. I know this might sound outrageous, but remember this was in 1969, when she escaped the Mexican prison. We know Kinne was using the Glabus name by 1973, when she and her husband arrived in Taber, Alberta.
She was, according to unsubstantiated sources, married to James Glabus in California in or around 1970. What name she used before marrying him, I do not know; subsequent documents relevant to her as Glabus, post 1973, apparently give her birth date as 11/30/1940 and born in Independence, MO. This is JUST a theory, but I wonder if Sharon used her maiden name of Hall upon marrying Glabus. The one year difference in birth year could be a deliberate "error" she put down early in her living as Glabus, to throw things off a bit. With no Social Security number, a date of birth is the next best thing for tracking identity. Sharon very well may have used her real birth certificate when marrying Glabus, or obtaining other docs.
Leaving the US for Canada would add an additional barrier for protection. If she has tried to do this today, she's be caught quickly. Also, using her original birth certificate and birth name would make a stable, verifiable foundation to overlay her new ID. She was known as Sharon Kinne from age 17, and possibly was briefly married prior! So most documents would have her married name, not maiden. Again, I speculated she deliberately caused confusion in records by reverting or changing her name, albeit not legally, and fudging her birthdate.