yeah I just ask because my moto g3 had the ghost touch issue but I (and a few others I've seen report online) would only experience it while it was plugged into the charger. Disappointing, but I just dealt with it because I really love the phone and it didn't do it that often enough to drive me crazy.
I think I may have noticed the ghost touch on my g4 plus too but again I figured it was because my phone was plugged in and it seems to happen less than the g3.
I hope she gets a good one for a replacement. It's a shame because the ghost touch is not an uncommon issue, but there's also plenty of g4s that don't experience this. Guess it has to be luck of the draw with moto g's anymore