Can my brothers underage daughter make decisions for him since he is on a ventilator My brothers wife is deceased
No. A power of attorney can only be granted to a competent adult.
Consult an attorney directly, so that the situation can be fully assessed, and you can be advised on all the available options.
Your brother's daughter should not be able to make health care or financial decisions for him if she is under eighteen (18) years of age. However, your question has relayed limited facts, and it is unclear what types of "decisions" your brother's daughter may have been asked to make or attempted to make for him. It is possible that if she is his only living immediate family, she may have been asked for guidance on his medical care, perhaps regarding her knowledge of what he would have wanted. That assumes that he is not mentally cognizant at this time. In general, if you believe your brother's rights are being infringed, you should certainly consult an attorney to ensure your brother is being properly taken care of and that his next of kin (who is the age of the majority) is tasked with making decisions for him (including medical and financial).
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