There is no power of attorney with the children or our mother. My sister is unable to write to or speak due to her condition. Her children are not making good health care choices for her due to lack of knowledge. Our mother and myself however have a medical background and could make better decisions. My sister is aware and her mind is good she can answer questions and can use an augmentive speech device now. she wants us to explore different options for he care but her children are not supportive and use the next of kin reasoning. Is there anything we as her mother and sibling can do?