"Isolation spring deep cleaning is turning up some fun old gems," Williams wrote on Twitter, where she also shared the photos with her 316,000 followers.
In the snaps, the late actor, who died in 2014, and his daughter are clearly having a blast hamming it up for the camera.
They posed with big, bulging eyes for the first pic. In the second photo, they're looking at each other and appear to be laughing hysterically. Zelda and her dad then flashed the No. 1 sign with their index fingers in the third photo. In the last one, she is covering her face while the "Mrs. Doubtfire" star points at her.
The sweet discovery has racked up more than 154,000 likes on Twitter since Williams shared it early Wednesday morning.
The 30-year-old is practicing the social distancing advice that the CDC recommends everyone follow right now to help stop the spread of COVID-19.
She seems to be spending the time tackling at-home projects.
"30 seems old enough to finally become one of those people who organizes their piles of old photographs in neatly labeled envelopes and acid free boxes... right?!" she asked her Twitter followers.
Fans were also in for a treat last December when Williams used the viral “Which Disney Character Are You?” filter and got the Genie from "Aladdin." Disney fans will remember that her father voiced the character of the Genie in the 1992 animated classic.