Bottom line for prosecutors: she obtained narcotics fraudulently. Duplicate scripts are proof. They see this a lot and aren't naive. If they were to make the effort to contact all three doctors, it would be apparent. It's then up to the prosecutor.
My best educated guess? Nothing this time. However, and here's where it gets insane: if she gets away with it and makes no attempt at getting clean, odds are she'll try again. Maybe it's time for your friend to get totally honest and stop jeopardizing her future.