Thank you for the answers.
So if I understand correctly, if I can't use my credit card I can't enable 1 click shopping so the gift card is not really a solution.
So I guess I'll have to consider registering my Kindle to her account. Or have her e-mail the books to me.
But if she e-mail the books, will I be able to put them in collections? As I understand I have to use amazon site to manage collections in my kindle.
MikeL: Are there other sites that sell e-books in kindle format? Or I have to buy them in ePub and convert?