I am not sure if this has been previously mentioned anywhere but I came across a thesis about Betty's writing.I must admit I haven't had time to read it yet but I was interested to see that her papers held in the University of Washington archives were mentioned in the bibliography.
Pat, thank you for posting and providing the link. I read through the thesis, (got bogged down a little in the statistical information), but enjoyed it. If the author had not quoted extensively from Betty's works, which lightened the material considerably, it would have been hard going. Interesting comparisons of authors contemporary to Betty; as far as I'm concerned, though, her talent outshone all of them.