Not to bash your friend, but it's clearly on one else's responsibility to determine what travel documents are necessary to travel other than the traveler. WAW-BUD is a Schengen trip. She could have boarded without showing a passport. That the AC agents didn't help is unfortunate but again, not their responsibility and it's stated in the terms of both the airlines and the ticket agent. Sad position to be in for your friend, but one of her own making.