to me faust is not a jewish name at all. dr faust or faustus who sold his soul to the devil?famous story.
so if that is the only reasn she thinks she is jewish forget it. any specal traditional rituals she remembers or stories ? any other names?traditionalists go by the matrilinear line for jewish descent.
she could al;ways have a malae relative test their dna for a more definitive answer (37 + markers for high resolution results) hope this answers it