You sound like a great friend. I'm truly sorry to hear about your friend, that is so, so tough. I have done a lot of research about SLE due to concerns with my young daughter
There is a Lupus site that is out of the UK and it is very active and very supportive. It was the best one that I found (it's been a couple of years since I've been there). It has a butterfly logo and if she introduces herself folks will respond. I think it could be a good start. Sadly it is not uncommon for people to have more than one autoimmune disease and sometimes two that can be very serious (like MS and SLE together) but your friend's situation is obviously very, very unusual. You sound like you are really hurting for this friend.