Technically, if sexual activity were to take place, the adult (in this case, the young woman) could be charged with statutory rape. Frankly, the four-year age difference is rather sizeable when one is so young and it would be a little bit strange for a dating relationship to occur with that age difference.
17 is the age of consent in NY. However, in order to be guilty of statutory rape with a 16 y/o victim, the defendant must be at least 21 y/o. While the female in this scenario cannot be convicted of statutory rape, she could face misdemeanor sexual misconduct charges. If the parties want to pursue this relationship, it would be advisible to wait until the boy's 17th birthday.
"Dating" is fine. Just know that even if you are not doing "it," there are other forms of sexual conduct (such as fondling, oral, toys) that may still carry legal consequences for the girl in your scenario. Ask a local attorney for a consultation which many will offer for free.
Generally the age of consent is 17 years of age in the State of New York, if anyone engages in sex with someone above the age of consent they may be charged with Rape.
I would suggest that you make the kids involved aware of the situation and if you feel you need the assistance of an attorney at any point, or are considering hiring an attorney you contact us directly at 212-405-2234.