Does type 2 diabetes always run in families?

Diabetes risks. Usually yes (due to genetic inheritance), but not always. Someone who has gained a lot of weight can develop dm2 even if nobody in the family has it. Sometimes it can happen randomly even without a lot of weight gain.
Yes but .... Yes , diabetes clearly runs in families , but for type 2 diabetes the most common type you can do things such as exercise and weight control to lessen your risk.