It really helps if you have your own business and can employ them there. You'll have to pay Social Security taxes on their earnings, but it's still a very good deal. You could also file returns for them reporting their mowing or baby sitting income, pay the self-employment tax, and fund a Roth with those earnings, or you could pay them for work performed around the house, and report that as well. For all of these, they need to actually do the work, and the amount you pay them has to be reasonable.