On Sunday, her burgeoning bump could be seen under black leggings and a white T-shirt as she took a lengthy stroll in the sunshine wearing a bright yellow face mask.
The mom-to-be was joined by her mother, her brother Patrick and his girlfriend, Abby Champion.
Shriver recently talked to ET about how excited she is about the impending birth of her first grandchild.
"I'm really proud of her. Obviously she and Chris are super happy," she said. "They're a blessing to each other."
Schwarzenegger’s proud father also recently gushed about how thrilled he is about becoming a grandparent.
"That is really exciting news to have Katherine now be pregnant and have a baby," he said during an appearance on The Tonight Show Starring Jimmy Fallon. "I don't know when exactly, but sometime this summer. I'm really looking forward to playing around with whatever it is, she or he is, and have some fun. I think this is kind of a unique experience."
Pratt and Schwarzenegger tied the knot in 2019, and in April, ET learned they were expecting their first child together.
Pratt also has a son, Jack, with ex-wife Anna Faris.