Unfortunately, things have gotten even worse. Green Man Review forwards a new note from Bartholomew that says, among other things:
Kage's doctor has informed us she has reached the end of useful treatment. [...] It is probably a matter of a few weeks, at most.
[...] I'll have her home in her own bedroom by the weekend [...], so end of life care can take place in more comfortable surroundings.
That first letter linked above contains contact information, should you wish to write to Baker via email or papermail. If you've liked her work, now would be a good time to let her know.
[For those who aren't good with author names, in case this means anything to you, Baker is best known as the author of the Company (a.k.a. Dr. Zeus, Inc) novels and stories, featuring immortal cyborg time travelers preserving important stuff throughout history. (I was amazed when I found out that the Alec Checkerfield stories and The Empress of Mars were part of the Company universe.)]