I have heard of Lupus occuring in more than one family member like an aunt and a niece. However, there a many people that are diagnosed with Lupus and have no other family member that has it. In my case, I don't have any family members with Lupus.
Also, if one family member has an autoimmune disease, it is not unheard of for another family member to develop another type of autoimmune disease. I hope this helps.