Dorice Donegan "Deedee" Moore, 39, will never be eligible for parole. Prosecutors said she cheated Abraham Shakespeare, 43, out of what was left of his lottery jackpot, killed him in 2009 and then concealed the body, The Tampa Bay Tribune reported.
Judge Emmett Battles described Moore as "the most manipulative person" he has ever encountered as he imposed sentence, WFTS-TV reported.
Shakespeare, a casual laborer, won $30 million in 2006, opting to take a $17 million lump-sum payment. He gave much of the money away and eventually agreed to let Moore manage what was left.
During the trial, Moore's attorney argued Shakespeare was killed by drug dealers and she helped hide the body and conceal his death because she was afraid she and her family would be harmed. Moore did not testify.
"I will not testify," she told the judge Monday morning. "It keeps my family safe."
Shakespeare's body was found in January 2010 under a concrete slab on property owned by Moore's boyfriend. His family reported him missing in November 2009, with relatives saying they had not seen him since April.