Yes, at least in theory. As a practical matter, the question has to do with your mother’s competency. By granting a power of attorney to your brother, your mother did not give away her rights. Furthermore, if it’s a financial and legal power of attorney, rather than one for health care, the power of attorney has nothing to do with decisions about where to live. Of course, your brother still holds the purse strings and has a lot of power over other decisions. Further, each of you acting in separate directions can be very disruptive. While your brother has no legal power over your mother, it would probably be better to find another approach other than acting unilaterally. We often recommend hiring a geriatric care manager who can help with assessing your mother’s capacity, determining where it’s safe for her to live, and mediating among family members.