We can’t tell you about New York law in particular, but the general rule is that no one has more rights than anyone else simply by reason of their familial relationship to the proposed ward.
If there’s a disagreement over who should serve as conservator, the court will consider many factors in determining who could best perform the role.
The relationship to the ward will carry significant weight – the actual personal relationship as opposed to the connection by blood.
Harry S. Margolis practices elder law, estate, and special needs planning in Boston and Wellesley, Massachusetts. He is the founder of ElderLawAnswers.com and answers consumer questions about estate planning issues here and at AskHarry.info.