Pretty low chances as others have said. Also, the genes are more likely to passed through the father's side than the mother's.

Even in people who inherit the genes, less than half go on to develop clinical diabetes. We don't know what kicks it off, so at this point there's not much you can do to prevent it. Several studies have indicated that breastfeeding may have a protective effect, however.

EDIT: Heres a website with an excellent chart showing a person's chances of getting diabetes depending on who their relative with it is:

http://www.genetichealth.com/DBTS_What_I...

(Read the section called Family Medical History)