Yes and no. Generally a power of attorney provides you with the power to control your father's finances and enter into contracts for him, but does not give you the power to decide where he lives, unless it specifically grants such power. Your sister also should not have this power unless your father granted it to her through a power of attorney or health care directive. Absent a guardianship appointment, your father has the right to make his own decisions in this regard. If he is not competent to do so, you may need to seek guardianship.