Rate from German mobiles is 34 cents. Not a bargain. Even callling German mobiles from the states is not a bargain. Best I've found is the MCI card. I think the rate is 15 cents per minute. Otherwise > 20 is the norm.
German land lines and CBW are worth while -- 9 cents?
Why not a prepaid card she can purchase locally either Germany or Lux in any of the countless call shops? USUALLY, they work in several countries. Suggest she start out with a LOW value card like 5 Euros to see how things go with the card. GO BANANAs and Hagenuk seem to be good options, but I cannot speak there from PERSONAL experience. I have used others -- names forgotten at this time.
Or you could try something like Enjoyprepaid (
www.enjoyprepaid.com) which she can use from landlines OR possibly cell phones. There are several local German #s. I combo with either the XtraOne 9 e-cents / min WEEKEND rate or the XtraNONSTOP option, calls TO US are relatively inexpensive (3 cents? -- I'd have to check, but the rate is low). The only drawback I see is that they don't show individual calls and charges. Ditto MCI. Ditto ATT.
Stan