I would guess it would depend on where she's traveling--eastern or western Europe? What are her options for cities? (ie--will she try for Rome or Pisa? Is she thinking Spain or Portugal?) certain Eu residents take vacation for weeks--frequently in July or Aug and the States is a prime target for them to fly here, shop and spend Euros, so keep that in mind. It aslo depends which gateway cities she can use in the US. You'll get lots of great advice with more details. We're here....