Tigger,
After reading the link in the last post, the answer to answer to the diabetes question is: no greater for her than anybody. Floating Kidney is an anatomical problem not a physiological one.
You don't tell us when she died (but if she had three generations after her it seems an 1800's birth date might not be out of place). Sure the site suggested it is rarely fatal, but what about when it is.
Was a Post Mortem performed to discover the cause of death and, on finding nothing else abnormal, ascribed it to floating kidney. If we give the medical practitioner all credit for reaching a diagnosis based on the resources at their disposal the real cause may have been overlooked because they did not have the diagnostic tool or the knowledge base to find the information or recognize the symptom.
I am making an educated guess, but the kidney might have strangulated if it was that mobile. If there was surgical intervention there are three ways that death might arise. Hemorrhage, a blood vessel was traumatised and not tied off. Anaesthesia always has a risk, lower today than previously but still a risk hence the degree of specialism, the early drugs were a break through but still "evil". Infection, if we are talking the age of carbolic acid before sulfonamides and certainly penicillin then infection can not be ruled out. But, then the death cert might be expected to reveal this death due to "X" secondary to "Y"
Interesting
Happy hunting
Canuc