Nadia Douglas was arrested at the scene Saturday on suspicion of causing serious bodily injury to a child. Douglas, who is 33, remained in Mansfield Jail on Monday on $500,000 bond. Jail records did not list an attorney for her.
Police responding to a call found her alone with the child in an apartment. Police spokeswoman Sgt. Kelly Peel says the child was bleeding heavily when police arrived.
The boy was being treated at Cook Children's Medical Center.
Marissa Gonzales, a spokeswoman for Texas Child Protective Services, says they will investigate the case.
She says CPS did not have any previous complaints on Douglas.