I have a British Airways household account (good for everyone at the same address), but as mentioned it doesn't sound like that will do you much good.

United does allow you to transfer miles from one Mileage Plus account to another, but they charge you 1 cent per mile plus tax and a transfer fee. It's not a great deal. I vaguely recall CO offering OnePass members the option to transfer miles for free during special promotion periods, but I have no idea if they've offered this promotion any time recently.