Detectives believe the woman is, in fact, the girl's mom and investigators are working to confirm the relationship.
"An investigation into the facts surrounding the circumstances described below revealed that the events occurred within the City of Sacramento," Sacremento County Sheriff's Office said in a press release.
The investigation will be handled by the Sacramento Police Department, officials said.
Detectives with the Sacramento County Sheriff's Office said people who have information about who the girl is should call investigators at (916) 874-5115 or contact Sacramento Valley Crime Stoppers at (916) 443-HELP.
People can also leave tips anonymously through the Sacramento County Sheriff's website at www.sacsheriff.com or by calling (916) 874-TIPS.