Hit and miss. I would say 50% John, as statistically you either (a) will, (b) won't. My dad was diagnosed type 2 at 56. I was diagnosed type 1 at 33, 3 yrs ago. My sister is not diabetic. My paternal grandad was type 2 and my maternal grandad and nan are type 2. None of their 6 daughters including my mom, obviously, don't have it.
I'm off the clock so forgive me but with cousins and their children it's about 6 in 40. Or about 15% for a mathematical answer. (Including my T2 cousin).
Phew.