According to the San Bernardino County Sheriff's Department, 44-year-old Bridget Sample was arrested after the victim was hospitalized with severe injuries.
Doctors determined the young boy's injuries were caused by non-accidental trauma, consistent with child abuse, the sheriff's office said.
The relation between Sample and the victim was not disclosed.
Sample is being held for several violations including torture and willful cruelty to a child.
Her bail is set at $500,000.
Anyone with information regarding this incident is encouraged to contact Detective Michael Erwin of the Specialized Investigations Division-Crimes Against Children Detail at (909) 387-3615. Callers wishing to remain anonymous may call the We-Tip Hotline at 1-800-78-CRIME (27463) or you may leave information on the We-Tip Hotline at www.wetip.com.