Hi & welcome. I'm so sorry that woman blundered so badly. (She needs retraining and a GAG!)
If you read the "sticky posts" (permanent info posts) at the top of the thread list, you'll actually see that there really isn't a single definitive test for lupus! To support a Dx of systemic lupus (SLE), you typically must meet 4 or more of the criteria, but not necessarily all at once. You'll also note some criteria are test results, while others are more like symptoms.
Also, there are other kinds of lupus other than systemic, usually milder, for in which you can meet fewer than 4 (like discoid = DLE, or subacute cutaneous = SCLE, or drug-induced = DILE). These are sometimes called "subsets".
I think you have the right to get copies of your daughter's test results, so why don't you ask for them? It's always a good idea to keep your own personal files.
In your shoes, I'd definitely take her to see the best specialists available. And as to whether it's lupus... I'm just a patient, but I do know that there are other conditions with overlapping symptoms (like juvenile RA, for just one example), so that's another reason to ramp up to the best experts you can.
But even if it is lupus---and I hope it's not---many people do pretty well in this day & age, with proper treatment & checkups. Sometimes lifestyle changes are needed, sun avoidance being a common one.
You could also visit your local library. Dr. Daniel Wallace is one excellent lupus author, and Dr. Robert Lahita is another. It's such a complex subject, and people can say such incorrect things---as you just saw, unfortunately.
I hope this gives you some ideas to work on while you both wait for her next appt. Please hang in there, both of you. I hope you post again when you have time, OK? Meanwhile, best wishes to you both, Vee