It depends on your airline. However, if 60,000 miles will buy the ticket, it might be easier for you to purchase the ticket with the miles in his/her name. My mom does this all the time (uses my dad’s miles to buy my tickets home). You’d have to get together and figure out what flight is best for them, but that shouldn’t be too painful. Otherwise, I know you can “gift” miles from some airlines, but I do not know if Northwest is one of them.