Divorse laws in NY State

My parents have been legally married for 30 years and together for about 38 years.  My father owed an apartment house when they got married but was only able to make improvements after recieving money durng the marriage.  My father was receiving a disability pension when they got married and outside of rent it was my mother you provided for the home.  My father convinced my mother to file jointly for their taxes, there was nothing taken out or his dissability checks but she always payed taxes and never got a refund...when she retired he then decided to file separately, this also coincided with him getting rental income from the apartment house.  He's never given her money for the household, food etc. comes from her social security check.  She has finally had enough and is ready to get a divorce, her health is very quickly fading based largely on their living situation, lots of emotional abuse including adultary.  My parents are both in their late 70's.  What are my mothers rights, what is she entitled to.  There was no prenuptial agreement.Thanks,