This is what I would do. I would go ahead and get Sydney what you want to get her for her birthday. Tell Dan what you are getting her and that if he wants, you will put from him as well, or he can get her his own gift if he wants. This way, you get Sydney the gift you wanted to get for her, he's notified so he doesn't go out and get her the same gift, or he can ask you to make the gift from both of you.
