[RAH]

You could set up her Nook with a separate credit card (i.e. another one of yours). I suppose this is obvious, but I am mentioning this because B&N provides the ability for family members to share books across multiple accounts, without buying the same book more than once.

It happens by credit card number. For example, if you and your husband have separately registered Nooks (different credit cards, etc), and you buy a book, he can get that book himself without buying it by using YOUR credit card number in a special B&N family arrangement. In fact, you can share a book you have purchased with anyone you are willing to give your credit card number to. (Note, this is not the same as the 2-week "sharing" option they tout, which is almost workthless, IMHO.)

I suppose you and your daughter are not apt to want to share many books, but if you set her Nook up with a separate credit card, you could then share (or not share) books between the 2 accounts without paying more than once for a given title.

I don't think there is any way to register a Nook without a credit card number so I see no way for her to have her own Nook without a credit card number.