Miles transfer--which airline?
 

My sister is coming from Europe and she does every year. It's Rome to Washington so about 8000 miles or so every time. I need to figure out which mileage program to put her on so she can transfer the miles to me without paying money. So which is best, these are the options:
United
Delta
British Airways
American Airlines

Help!!

AFAIK, no program allows free transfers, but BA does have family accounts. If she signs up for BA, you can create a family account with both of you in it and use the miles that way. Or, you can just book awards directly out of her account and not bother trying to consolidate anything.