Advice for helping sister-in-law please

Dear RA community, My sister-in-law is a very youthful active 71-year old and a lovely person. Recently she was told by a rheumatologist she has RA and was put on 200mg Plaquenil plus NSAIDs. Because I have had SLE (lupus) for nearly 40 years with many ups and downs/flares and remissions, she is asking me for advice. Of course I referred her here and to reputable national medical sites.

Here is the immediate issue: her labs on which the DX was made were as follows: ANA 1:40; no RF factor; all other values normal except a very slightly low C3 and C4 ( as in one to five numbers off normal) and her typical low white blood cell counts.

She went to a rheumatologist at a very reputable hospital and got the DX of RA. However she only has joint pain in one hand, and she is very active and does have the kind of fatigue that is more typical of autoimmune diseases (I understand the huge gap between fatigue of say lupus, versus non-patients who get tired—-she seems to have the latter, zipping all around, doing sports and arts and keeping up an active travel schedule and lots of stuff I couldn’t have done as a 40 year old.

Unfortunately I blurted out that I wondered if she actually had RA and shouldn’t t she get a second opinion? I regret that—-I wasn’t trying to minimize her situation but really, is this a typical RA pattern? The people I have known with RA have serious, serious fatigue and pain and screaming high labs like sed rates (hers: very low) and with RF factor positive.

What do I do/say to help, once my foot is out of my mouth and I apologize to her for saying that and doubting the DX?