Sparkle Daniel was found guilty of second-degree murder earlier this month. Bronx Supreme Court Justice John Carter called the crime "despicable" as he sentenced the 25-year-old woman on Monday.
Prosecutors said Daniel and another woman poured wine down 91-year-old Nellie Hocutt's throat and stuffed her mouth with a piece of cloth before suffocating her with a plastic bag.
They say the suspects bound the woman to a chair with tape and a telephone cord.
At the time of their arrest in 2007, police said the women had decided to rob Hocutt of a gold chain and some towels.
The second defendant is awaiting trial.