Melanie Reyes, 20, was in critical condition at Ocala Regional Medical Center, the Marion County Sheriff's Office said. Her son, Jonah Mendoza, who was the object of a custody battle, was pronounced dead about 1 p.m.
Police said they were asked to check on Reyes at her home after a relative spotted a Facebook posting indicating Reyes planned to commit suicide. Police said they recovered a handgun at the home and found no evidence of anyone else on the premises, the Star Banner newspaper in Ocala, Fla., reported.
Reyes was involved in a custody battle with Jonah's father, Jordan Mendoza, who had petitioned to establish paternity and arrange for visitation.
She also was facing aggravated domestic battery charges for allegedly hitting her current boyfriend, Marcelino Febo, with a baseball bat. She told police Febo had knocked her to the ground and called her names.