Complications - roughly when do they start showing up?

I am the first cousin and Power of Attorney for a 62-year old female with uncontrolled type 2 diabetes.  She was diagnosed with diabetes during hospitalization for gallbladder surgery in 1997.  Her height is 4’10” and she weighs 195.  My cousin is not motivated to restrict her diet or exercise to better control her disease.  The A1C this month was 8.1.  She frequently sees various doctors.  Her primary care physician keeps increasing her medications trying to counteract her poor diet and lack of exercise.  My question is, on average how many years after diagnosis do complications begin in cases like this?  Thank you.

[WaveRider]

"...on average how many years after diagnosis do complications begin in cases like this?"
Considering there has been 12-13 years of negligence, diabetes complications began years ago. Some may be more noticeable than others such as fatigue, thirst, and frequent urination. Others might include blurred vision, poor wound healing (cuts, scrapes, etc.) and/or recurrent infections, dry mouth, and dry or itchy skin. Serious complications are retinopathy and neuropathy in hands and feet.