Lower her salinity to 1.009 [in a dedicated tank] over the next 48 hours and see if that will help her, poor thing. If you have got anything you can put her in...or if it's a small tank, just remove your live rock and sand to buckets and put her in the bare tank until you can do more toward getting a quarantine/hospital tank.
Nems are very dangerous in a tank, and shouldn't be added until the tank is about a year old. I'm now worried about your neighbor: ich is a parasite that falls from the fish to the sandbed, and will lodge cysts in the sand, rock, and filter medium, that will hatch into hundreds of ich swimmers and head for other fish.