Erika McCauley, 37, pleaded guilty to stealing the money from the comedian over the past several years. She was also ordered to pay Cook restitution and to surrender all interest in the properties and business ventures she obtained with the stolen money, The Boston Globe reported.
McCauley and her husband Darryl, Cook's half brother, transferred funds from Cook's business and personal accounts from 2004 to 2008. Darryl McCauley was Cook's business manager until December 2008. He pleaded guilty for his role in the case last month.
Prosecutors said Erika McCauley used the money to buy hundreds of thousands of dollars worth of jewelry, homes, condominiums and businesses in Maine and Florida.
In addition to prison time, McCauley was sentenced to probation for 13 years on two counts of larceny over $250, and conspiracy to commit larceny.
Cook, 38, rose to fame doing stand-up comedy and has released several full-length comedy albums. His next movie, "Answers to Nothing," will be released this year.