By the time my kids hit 15, they bought the presents for their own friends. They tended to make a card, and give their favorite candy bar or something like that.

Yes bring a gift like for any other birthday party. My DD;s birthday is in June but one year she wanted to go to a specific CHristmas play so her party wasn't until December. We still got her a cake and sang her happy birthday, too.

Do you know if the teen and family had crazy winter/spring seasons? If they're late teens, maybe they wanted to put it off til after testing and exams?

If it's a birthday party, bring a gift.

DD was invited to a birthday party this weekend for a friend whose birthday was in January. Seems a little late. What are your thoughts on expectations for a birthday gift? Kids are late teens, and it's coed, not 'hosted' by parents. Should she bring a gift?