Getting Married - need to book ticket for after name change
Book it in her old name, have her use her Driver's lisc with old name, use her existing sky miles account.
When she returns, have her fax wedding cert/lisc to listed Delta sky miles group and they'll change her name.
Did something similar right after I got married. Seemed neater than switching everything over and trying to get it combined (and made it easier on my wife).