You could have a clogged fuel filter because the place she bought gas was near empty and some sediment got pumped into your tank.
Or it may have pumped up some water which had condensed on the inside of the underground tank... that is prone to happen when those tanks are low, too. Or not emptied and refilled often enough.
Go by AutoZone, Advance Auto, or someplace like that and get one of those "gas dryer" products and dump it in, then slosh it around a bit by rocking the car back and forth by pushing down on a rear fender or driving over some speed bumps.
If that doesn't work, you may have to replace your fuel filter.