The time limit on the Eurail pass only becomes active after the first time you use it. So if your friend does not use her pass until August 8th then that is when the pass is activated. As long as the activation date is within 6 months of the purchase date. That is the only thing you have to be aware of. As a non-European you can also buy Eurail passes (from here
) while you're in Europe and have them shipped to you (as long as you have an address - like a hostel or friend - so you can pick them up).