During her appearance Thursday's "Watch What Happens Live With Andy Cohen," the Arrested Development" star was asked if she got "the chance to meet the future princess" when she was on The CW teen drama series.
After her jaw dropped at the news of Markle's "90210" cameo, Walter -- who played Tabitha Wilson on "90210" -- replied, "You know, I didn't know Meghan Markle was in the reboot."
"She was the girl performing oral in the car," Cohen clarified of the risqué part.
"Are you serious? I wasn't in that scene," laughed the 77-year-old actress.
As for the recent royal wedding, Walter said she thinks "it's wonderful what [Markle] is doing."
"They seem so happy and in love," she shared. "I hope it goes on forever."
While Walter was more than willing to chat about a former colleague on "90210," she did not address the recent allegations against her "Arrested Development" co-star, Jeffrey Tambor, in which she accused him of verbally abusing her.
"Let me just say one thing that I just realized in this conversation," she shared during a cast interview with the New York Times. "I have to let go of being angry at him. He never crossed the line on our show, with any, you know, sexual whatever. Verbally, yes, he harassed me, but he did apologize. I have to let it go."
"And I have to give you a chance to, you know, for us to be friends again," she said, turning to Tambor, who was just sitting a few feet away at the time. "Almost 60 years of working, I’ve never had anybody yell at me like that on a set and it’s hard to deal with, but I’m over it now."