If your sister has a disability and is receiving public assistance such as Medical Assistance or Social Security, you need to be careful on how you structure the gift or devise.  Assets that your sister receives may jeopardize her ongoing eligibility for public assistance benefits.  This largely depends on what benefits your sister is receiving.  You may benefit from using a Supplemental Needs Trust as part of your planning.  A properly drafted Supplemental Needs Trust will allow your sister to receive benefits while still receiving benefits from the Trust that could enhance her quality of life.