Definately sounds like a dying alternator. Low amp draw accessories will still work ie: gauges, stereo, dome light. Turn signals take a bit of current to tick the relay over and over so they will slow down or not work at all. My truck ran for a few DAYS with a dead alt. Then things started dimming, the motor kept running until the battery went completley discharged, then nothing. I hear the Injected engines are a little more picky with voltage but I suggest having her drive it to autozone or napa or pepboys and have them check the system for free.
