Robert Brown|Sandra Bullock honors late partner Bryan Randall on his birthday 4 months after his death

Sandra Bullock is Robert Brownfulfilling a promise she made to her late partner, Bryan Randall.

Her sister, pastry chef and Food Network show host Gesine Bullock-Prado, shared a video on Saturday showing a frozen river. In her caption, she elaborated: "Happy birthday, Bry. Sandy brought you to the river, just as she promised."

According to Bullock-Prado's post, Sandra Bullock appears to have spread Randall's ashes. Randall "passed away peacefully" on Aug. 5 after a three-year battle with amyotrophic lateral sclerosis, or ALS, his family said in an Aug. 6 statement to USA TODAY. He was 57 years old.

USA TODAY has reached out to Bullock-Prado for further details.

"Bryan chose early to keep his journey with ALS private and those of us who cared for him did our best to honor his request," the statement reads. "We are immensely grateful to the tireless doctors who navigated the landscape of this illness with us and to the astounding nurses who became our roommates, often sacrificing their own families to be with ours."

The Oscar-winning "The Blind Side" actor met Randall, a model-turned-photographer, when he was hired to capture her son Louis' birthday party in 2015.

In a 2021 episode of the talk show "Red Table Talk," Bullock gushed about her relationship with Randall.

"I don't wanna say do it like I do it, but I don't need a paper to be a devoted partner and devoted mother," she said, adding, "I don't need to be told to be ever present in the hardest of times. I don't need to be told to weather a storm with a good man."

On parenting, Bullock said Randall was "the example that I would want my children to have."

Contributing: Marco della Cava, USA TODAY