Does my 13 yo niece have to agree to me adopting her?

My sister passed away unexpectedly a year ago and her daughter, my 13 year old niece, has been bouncing around from relative to relative since then. Her father and my sister divorced when she was a baby and he’s never really been in her life. He did not show up at the funeral to claim my niece. She has not been doing well since her mother’s death, failing school, not attending her sports, and using alcohol with her friends. My wife and I would like to adopt her and give her some stability, help her get back on track. If we adopt, I can put her on my health insurance, include her in my will, and get her other benefits through my work. Unfortunately, she says she doesn’t want to be adopted because it would be a betrayal to her deceased mom. Does she have to consent to an adoption here in New York and if she won’t, is there some other legal means we can pursue to legally be able to care for her. Perhaps custody or guardianship?