A day (or night) doing something she likes that is not your thing, does she like theatre, dinner shows, whatever. Mainly something that shows you thought about it and wanted to give something she really wanted. I knew a married woman who had a busy husband and 3 kids, her husband gave her a card that said something about wishing that he could give her more of his time but that since he couldn't he would at least give her a little of her own, the card contained 10 days worth of vouchers for babysitters to watch the kids. She said it was one of the best gifts she had ever gotten.