At the Los Angeles, California, event on Thursday, Parrish said she was "heartbroken" upon seeing Mitchell's New Year's Day Instagram post revealing that she "miscarried and lost the child of my hopes and dreams" in 2018.
"I respect her bravery so much," Parrish said of the 31-year-old, who's reportedly been quietly dating TV host Matte Babel since January 2017. "That can't be an easy thing to talk about, and a lot of people go through that and I think she can inspire people for the hope of, you know... life still going on and still amazing things still happening. It's horrible."
"My heart really goes out to her," she added. "It's heartbreaking."
"I'm so happy for Troian with her sweet baby girl," Parrish gushed. "I hope to meet her soon."
Despite PLL coming to an end in June 2017, Parrish is keeping a bit of Rosewood alive in a new spinoff series, The Perfectionists. Though Sasha Pieterse is also returning to her PLL role in the series, Parrish admitted that filming without the rest of the core cast was "weird."
"You know, you step back into Mona's shoes and that felt natural," she said. "But to kind of, like, look around and be like, oh, we're in a new town -- quite literally, filming in Portland -- with some new faces, and you feel blessed that you're able to still be here and expand your family, but you definitely miss the originals. Absolutely."
For Parrish, she simply hopes that fans will tune in and embrace the show's "newness."
"I want [fans] to know that we are respecting the Pretty Little Liars world still," Parrish said. "It's still very much PLL. We're giving you Ali and Mona, we're staying true to our characters -- to the vibe of the show -- but there will be some fun, new faces and new mysteries and I hope that they kind of embrace the newness of it."
Watch the video below for more of what to expect when The Perfectionists debuts later this year: