Yvette Harrell killed another woman while six weeks pregnant.
She says her unborn child is being unlawfully detained while she is currently incarcerated and waiting for trial.
According to Ms. Harrell's attorney, jail personnel have endangered the child by "failing to provide reasonable and necessary prenatal care" in an emergency petition filed in a Florida court.
The argument draws on the concept that a foetus is a person with rights.
Since the US Supreme Court overturned the general right to an abortion, known as Roe v Wade, last summer, the notion that an unborn child is a person with constitutional protections has gained popularity.
Ms Harrell's "unborn child is a person as defined under the Florida Constitution and United States Constitution", attorney William Norris wrote in a legal submission.
The filing was made on behalf of the unborn child and calls for Harrell to be discharged from jail until the child is born so she can receive proper care.
Even though it's still inside its mother, an unborn child has rights, according to Mr. Norris, who spoke to The Washington Post. "In this detention, the unborn child has been denied the protections of due process of law. ".
Since she shot Gladys Yvette Borcela, whom she was riding with in an Uber, Ms. Harrell has been detained without bail in Miami-Dade County.
The 24-year-old has pleaded not guilty to second-degree murder.
According to Mr Norris' petition, Ms Harrell acted in self-defence, "in fear of her life and the life of her unborn child".
He alleges that, in jail, his client has not received the prenatal vitamins, food and liquid she needs or been taken to her scheduled doctors appointments, and was at one point left in a transport van without air conditioning while temperatures soared over 100F (38C).
Ms Harrell's last medical examination was in October, Mr Norris added, making it unclear how far along the pregnancy is or when the baby is due to be delivered.
In a statement, the Miami-Dade County Corrections and Rehabilitation Department said it was "conducting a full review of the health services offered and received to ensure that all pre-natal care being provided in our custody is appropriate".
On Monday, Florida Attorney General Ashley Moody's office called for the petition to be dismissed, noting it did not include adequate evidence to support Ms Harrell's claims of neglect.
But Michael O'Brien, the father, told NBC Miami he was concerned for the child's wellbeing.
"I don't want the baby to be born prematurely or low birth weight," he said. "The conditions are terrible and I feel she's not getting the pre-natal care she should be getting. ".
