You could read books but they tend towards the medical facts and although it's good you learn some of that it doesn't cover how a patient feels.
For an overview of the facts AND feelings side please see our new film 'Lupus? Whats that?' Free to view at: http://www.lupus.org.uk/information/information_lupuswhatsthatfilm.htm
There is also a lot of information about lupus on our site and also patients have written their stories there too: http://www.lupus.org.uk/whatislupus/whatislupus_patientstories.htm, again by reading those you'll get a good understanding of how patients feel.
I'm sure she'll tell you what she wants you to know, eventually probably the whole story but I'd just let her tell you in her own time. Every lupus patient is very different and the severity of their illness is different too. However lupus is just part of us not all of us so I'm sure she'll want to talk about all the other things that make her who she is and not just her illness.
It's a good start that you are taking the time and effort to understand lupus so that bodes well
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