Article 81 of New York's Mental Hygiene Law describes an incapacitated person as being anyone who struggles to take care of his or her financial affairs or property. In instances where it can be proven that they're unable to do this, the state allows for a guardian to be appointed to oversee the handling of these matters for them.
Before a petitioner is allowed to serve as guardian to another adult, a judge will have a court evaluator appointed to the case. That individual will be responsible for setting up a meeting with the alleged incapacitated adult to see what decisions that they're capable of making.
There are a variety of reasons that a court evaluator may deem an individual to be too incapacitated to handle their own property or financial matters such as sudden-onset mental illness.
The Queens' court evaluator will ultimately make a report to the judge presiding over the matter as to whether that disabled individual should be appointed a guardian. If they decide that they should, then they'll also be responsible for reporting back to the judge about how much power over the incapacitated person that the guardian should have and how long it should remain in effect.
Requests made by one party to establish a guardianship over another are required to be brought before either a county or Supreme Court judge in the state. Before any guardian is appointed, a hearing must take place in front of them. If you want to give yourself the best chance of becoming a guardian to a loved one, then an estate planning attorney can help you strategize as to how to make that happen.