I think you missed my point. Look at that suicide note and tell me that it wouldn't serve a killer's interests perfectly. It's weird for a suicide note -- no emotions, no apologies, no thank you's or "I'll miss you's...not even a hint of explanation as to why she would commit suicide. And she signs it "Jane Doe?" Not to mention that it wasn't handwritten, it was typed. As a suicide note it had all the emotion of a grocery list.
SUICIDE NOTE: "Deceased by own hand
prefer no autopsy
please order cremation with funds provided
Thank you, Jane Doe."
Now imagine that a killer had created it. Suddenly, everything that didn't make sense before makes perfect sense now. Why it was typed, why full sentences were not used, why she didn't sign it with her real name, why she stresses the point that SHE killed HERSELF (effectively using a suicide note to identify itself as a suicide note), and why she would care about whether an autopsy was performed given that, afterward, she was going to be turned into a smoldering heap of ash anyway. It even explains the police contact the next day, when she was already dead at that point. A woman calls in, claiming to be Shirley, and voila...documentation of her being alive at that next day, which would effectively rule her out as being the woman who had died in the cemetery.
Don't get me wrong. This is just conjecture. I have no way of knowing what really happened to her. But there are so many things about this case that don't make sense, unless you look at it as a murder (or even assisted suicide).