This kind of thing depends hugely on the store involved. I've tried to buy gift cards for people in North America, and sometimes succeed, and sometimes not.
If the website itself has a gift card option that lets you select her address for delivery, and then lets you put in yours for payment, that is a good start, but unfortunately, many times the payment address also has to be from that country or in that format. It's really frustrating, because there's often no reason why they can't accept a card from abroad, other than their website isn't set up for that.
So sometimes I get around it by using PayPal, which doesn't always require entering a billing address in the company's web form.
Other times, I have had to email the company separately and ask, and sometimes they can do it by email/phone, or can send an invoice by email.
Even big companies like Starbucks and Apple make this sort of thing much more difficult than it needs to be, especially when they sometimes have country-specific web pages that are difficult to get out of when you want to buy something on one from another country.