I am not a big fan of Stress Coat. Fish can replace their slime coat fairly easily...& it's just my thinking that aloe is, yep, slimy. But it'll go all over the injured/sick fish including the gills, over the other fish, their gills & decor too. Does it interfere with gill function? I don't know...I don't freak out if a LFS adds a squirt of it to a bag, I'm not allowing shop water in my tanks if I can possibly help it...& it's only for 30-60 minutes or so. Aloe also irritates my skin...is that maybe how it "helps fish slime coat" by irritation (again, gills ?)?
If she doesn't look to be improving after a week or 2 of frequent clean water (what can be more "natural" than clean water?) &/or starts to look worse, I'd go with a real antibiotic drug not a "natural product". (disclaimer, my husband is a retired organic ag/pharma chemist. We believe in proven drugs not wishful thinking)