The TODAY special anchor's daughter, Katherine Schwarzenegger, 30, is expecting her first child with husband Chris Pratt, 41, which has Shriver, 64, looking forward to a new phase in her life. (Just don't call her "grandma.")
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"I've started to get really excited, actually, about it," Shriver told Hoda Kotb as she guest hosted the fourth hour of TODAY on Monday. "This last 4 1/2 months, I think, I've gone like everybody else through this whole wave of emotions. You've been like, 'OK I can manage this, it's gonna be over in a little bit.' Then you get depressed, and you're like, 'My God, what's happening?'
"And this has been kind of a little light there, right? It's something to look forward to when we don't really have much to look forward to."
Shriver is looking forward to being a fun grandmother playing in the backyard with her grandchild.
"I'm excited, I'm nervous," she said. "I don't know what it's going to be like, but I think I'm going to be a great grandmother because ... I'm gonna like spray the sprinkler, I'm gonna do the three-legged races. I'm gonna hopefully have a partner in crime again."
Shriver, who has four children with ex-husband Arnold Schwarzenegger, is excited to return to that playful spirit while spending time with her grandchild as he or she grows up.
"Obviously, there's great parts about having adult kids, but little kids, right, they kind of just are like awed and excited about getting a ball, playing catch, all of these kind of simple things," she said.
She feels the pandemic has stressed the importance of family more than ever.
"I think this time has brought so many of us back to the simple things," she said. "Eating with our families, cooking, playing ball. I think it's been challenging, obviously, for having little kids at home with home schooling.
"I have a lot of people who talk to me about that, but I think if you're lucky enough to have a yard, if you're lucky enough to be able to run in the sprinklers, if you're lucky enough to do something like that, I think that's rekindled the joy of those moments for people."