If she plans to use a credit card to get cash, I would advise against it, since the interest on cash withdrawals, via credit card, could be upwards of 20% (per year).
If she still decides to use her credit card, it would be in her best interest to pay off the balance as soon as possible, within a few months, preferably. If I were in her shoes, and planned on only using a credit card, I would charge as much of the trip's expenses as I could (plane ticket, accommodations, etc.), and withdraw as little cash (for spending money) as possible.