I do not know if you know this but if your Grandmother had Lupus, you are predisposed to it also. Sometimes Lupus skips a generation like my friend who is 43 and has it, yet her Mom does not and her Grandmother died of it mainly because she was misdiagnosed with depression (Lupus effects the brain) and was not treated until it was too late. The Doctor that misdiagnosed it made a complete turnaround and now that is all he does because he has a modicum of decency. You really need to make sure you do not have it, gastro problems are one of the first signs. My friend had stomach cancer when she was in her 20's and she is lucky to still be around. You have to get with a really good Rheumatolgist and it may take a few visits and bloodwork before you have a real diagnosis, and Lupus is a Progressive disease that you have to watch carefully. Good luck.
We do things weird in my family. Gramma got lupus at 70, my brother got Gillian Barre (which usually hits people in their mid 40s and later) when he was in his mid 20s, and I got Guttate psoriasis, which you are supposed to get in your teens, when I was 47 (only one dose, but it's enough to make me sure to go to the dr. if I even suspect strep throat, which can set it off).
But I've been making gallstones since I was 17 or 18. No gallbladder and I still make'em. I will keep an eye out for symptoms of lupus since we have autoimmune thingies in my family background, but so far, the arthritis I have is wear and tear from writing and crocheting and knitting too much...and I've had that since college, about 20 years.
Prevention magazine had a nice article this summer about 7 diseases you need to watch out for to make sure they get diagnosed properly, and Lupus was definitely one. Also included women's heart disease symptoms and the early signs of ovarian cancer. Worth reading.
My doctors watch for that in me also giant cell arthritis.