Someone posted earlier that in NYS a sister can make decisions.
https://ag.ny.gov/sites/default/files/advancedirectives.pdf
IF YOU DON’T HAVE AN ADVANCE DIRECTIVE
If you have lost the capacity to make decisions about your medical treatment, and have not appointed a health care agent, a person close to you may make decisions on your behalf. In 2010 the New York Legislature passed the Family Health Care Decisions Act (FHCDA),7 which allows family members and others who are close to you to make decisions regarding medical treatment in accordance with your wishes or, if unknown, your best interests. The “surrogate” decision maker would also be permitted to direct the withdrawal of life-sustaining treatment (including consenting to a DNR order).
The best way to ensure that your specific wishes are met is to
select a Health Care Proxy and complete a living will as described in this booklet. Otherwise, you will not be able to control how you receive care while you are incapable of making a decision.