If they live in a state that allows it, the referral program is:
1st=$200., 2nd=$350, 3rd=$500, 4th=$750, 5th=$1,000 that can be taken in Disney Dollars, applied toward your Mtc. fee, toward an add on, given to charity. No Cash.
You'll get a form to fill out after your sister closes on the contract..probably 4-8 weeks after.