I don't know if a soak is necessarily going to help a developing RI.

Chances are she is just fine. Either she is hissing at you or she has a little bit of stuck shed in her nostril. If you notice any other symptoms of an RI (open mouth breathing, mucous, bubbles) then it would be a good idea to make a vet appointment.

Don't preoccupy yourself with looking for problems with your snake. More often then not, people over analyze "problems" they think their snake has. Just relax. You will notice if an RI develops. There isn't much you can do to get rid of it without antibiotics.