One should be able to order a second personalized card for the SmartyPig Cash Rewards card. I am sure many would find managing two accounts one for one's self and another for one's spouse to be inconvenient.
This would be good for older children as well. It would be nice to be able to give them a card that I am able to transfer funds too. They may not meet all the requirements to setup their own account and simply make me co-owner.