+1 on leaving their accounts to accrue. One of my daughters is actually doing a mileage run in August in order to book her next year's J/F TATL. Ok, so she hits platinum too, and I promised her a nice lunch and a new fuzzy toy in MIA, but essentially, she is sitting on a plane for no reason other than I'd rather pay for this and boost her account to the required miles than pay the gift/buy/share fees.