Police were called to the woman's mobile home after receiving a 911 call about a woman suffering chest pains.
But when officers arrived, the woman pointed a gun at them and threatened to shoot anyone who came near her.
The woman stayed put despite police using flash grenades and tear gas.
The standoff in the town of Topanga, near Los Angeles, finally ended early on Friday after the woman attempted to crawl under her mobile home and police pulled her out.
"It's very unusual, but we're just happy that we're able to bring this to a peaceful resolution," said Lt. A J Rotella of the Sheriff's Department's Malibu station told the Los Angeles Times. "No-one wants to see an elderly woman, for whatever reason she acted this way, no one wanted to see her get seriously hurt."
It was unclear whether the crisis-negotiation robot was damaged in the incident. The woman also hit it with a broom and threw a cover over it.
Some police departments in the US use the robots - equipped with two-way radios and cameras - to scout dangerous situations and establish communication between police and suspects.
An elderly California woman has surrendered to police after a 22-hour stand-off, in which the woman shot at a police robot that was sent to communicate with her.