You asked that
here half a year ago and I answered you there.
With Vodafone Call'Ya your girlfriend will be charged € 0,20 or € 0,30 per 10KB + € 0,06 for each begun hour of data usage. So she'll pay at least € 20,06 or € 30,06 per MB.
Your girlfriend should better switch to either solomo pro or Fonic, where the later is available nearly everywhere in Germany and offers data for € 0,24/MB, calls within Germany for 9ct/min and to whole Europe starting from 9 ct/min and SMS to Germany and whole Europe for 9 ct (see:
http://www.prepaidgsm.net/forum/euro...-visitors.html).