Is this a kidney stone, or worse?

My mom has been sick for about a week now with terrible pain located around the left kidney. She recently has come up with some other symptoms like nausea, high fevers, chills, stomach bloating (huge amount of bloating), almost complete lose of appetite and thirst, reddening of the skin around where the pain is, and lack of sleep. She had an appointment scheduled three days from now, but me might end up running her into the emergency room. I thought she might have a kidney stone, but then she started getting the bloating and the redness. I'm really worried. What would cause her to actually redden on the skin around the area of the pain? I'm worried she might have an infection. What do you guys think? I would like to get an idea of what might be wrong with her.