She wept as she listened to replays of calls she made to 911 to report her granddaughter, Caylee, missing, the Orlando Sentinel reported.
"I found my daughter's car today and it smells like there has been a dead body in the damn car," Cindy Anthony said, sounding frantic.
On the same call, Casey Anthony can be heard telling the operator her daughter was last seen with her nanny. The supposed nanny turned out not to exist.
The judge called a 5-minute recess to give Cindy Anthony time to compose herself.
Caylee was last seen on June 16, 2008, but was not reported missing for 31 days. Prosecutors say Casey Anthony killed her daughter by smothering her with duct tape, while the defense says she drowned accidentally in her grandparents' swimming pool, and Casey and her father, George Anthony, hid the body.
George Anthony testified last week, denying the defense story. He also said he did not molest Casey when she was a child.