It's not for sure that you'll get diabetes. In fact it tends to skip a generation.
What you should do is to get your blood sugar tested once in a while. Every couple of years is enough. If you get regular medical checkups it will definitely be included. But if not, your mom, or any other diabetic you know, probably has a glucometer (a gizmo to measure blood sugar) and would be happy to test you.
If your blood sugar starts creeping up, you can begin eating/exercising like a diabetic. Low carbs, regular exercise (like walking for 45 min. 3x a week, or riding a bicycle). Then if you do become diabetic, you won't have already done some damage to yourself.
Long-term high blood sugar causes horrible 'complications'--like kidney failure, blindness, gangrene and amputation, etc. MANY diabetics don't know they're diabetic until they've already done some damage. So it would be good to know ahead of time and take measures. Blood sugar control is done through diet and exercise. And this is good for a healthy person too, so there's no downside risk to behaving like a diabetic even if you aren't one.
I'm diabetic myself. My mom's parents' generation had it, not my own parents. I thought it was like the end of life, but really, if I'm careful about what I eat, and if I get on my bicycle 2-3 times a week, it's not a problem at all. I'm not 'sick' or anything. And I've already exceeded my grandparents' life expectancy.