Alexandra V. Tobias pleaded guilty to second-degree murder on Wednesday and remains jailed.
The Florida Times-Union reports that she told investigators she was angered because the boy was crying while she was playing the game FarmVille.
The paper also reports that she told investigators she shook the boy, smoked a cigarette to compose herself and then shook him again.
Tobias called 911 on January 19th, saying the 3-month-old was not breathing, CBS affiliate WTEV reports. The baby died at the hospital from head trauma.
She will be sentenced in December. State guidelines call for 25 to 50 years, but a prosecutor said it could be shorter than that.
A telephone message and an e-mail sent by The Associated Press to her attorney weren't immediately returned.
FarmVille is a game that allows members of Facebook to manage a virtual farm by plowing land, harvesting crops, and raising livestock.
This isn't the first time a virtual online game has been linked to a baby's death this year. In May, a of abandoning their newborn daughter, who starved to death while they addictively played an online game raising a virtual child.