Smiled, hello and welcome! I'm sorry for the problems that bring you here. I'm just a patient, so please read in that light, OK? For starters, have you seen the "sticky posts" (permanent info posts) above the user threads?
I can't know whether you have lupus, but that said, I'm glad you had more tests done because it sounds possible to me. If it does turn out to be lupus, please know that many people do well in this era of ongoing checkups and modern meds.
I had some of the same problems you list. The one you mentioned that struck a huge chord is "growing pains", which is one of the "alternative criteria" in the sticky posts above, btw. Mine started at 13, which distinguished me from my classmates, I suppose.
I had urinary problems, too: no blood but stones once in awhile, and pain, urgency and frequency. Also migraine-like headaches. (Yours starting so young, at age 3, sounds awful.) I also had photo-sensitive rashes that were proven lupus-specific via deep-punch biopsy. I've done MUCH better on medication but must avoid sun, alas.
To help your mom, you could visit your lending library & borrow books on lupus, and maybe introduce her to the site here? I hope you post again soon, also let us know how your labs turn out. Warm wishes to you & to your mom! Hugs, Vee