I have two things to tell you.
Even if you have your close relatives suffering from SLE it is not necessary that you will also get it. Of course the chances of getting it is somewhat higher in you than in general population. But, it is not anywhere near 100%. Therefore, I would strongly advise you not to worry about this issue.
Even those persons who have SLE are now-a-days leading almost a normal life with such effective medicines that are now available with little adverse-effect.