She's Killin Me Here ... Could Use Some Tips on Living With the Elderly

Well, from a diabetic:

Low blood sugar causes me to be scatterbrained, and not be able to analyze complex problems.

High blood sugar causes severe lack of motivation and borderline depression.

Have you ever actually seen her measure her blood glucose level?
If so what was the number?
Reading should be taken about 1-2 hours after a meal.

People who aren't diabetic normally don't ever have a number over about 120.
The normal range is 80-120.
Over 150 is time for serious diet modification or medication.
Under 50 is likely to cause fianting and possible death if no assistance is rendered.