The 23-year-old actress -- who starred as Clary Fray in the Freeform hit show, based on the YA book series, The Mortal Instruments, from 2016 to its final episode in May -- shares in ET's Unfiltered series that the show and its fans had a massive impact on her.
"I've never played a character for that long before, but getting to live in Clary's shoes for the better part of four years and build those relationships, they took a life of their own, and that was part of the magic of shooting the last season and shooting the finale," the Kansas City, Missouri, native shared. "I give so much credit to the fandom fueling us as we created this show. It became a team. They're a part of the family."
"I was cast in Shadowhunters when I was 19 on sort of a precipice of life and adulthood and a lot of changes in everything that is my existence," she continues. "And to be surrounded by a group of people on set and by a fandom that is so caring and so diverse and really helped shape me to the person that I am today. I'm 23 now and having come out of this show a completely different person, but undoubtedly for the better. And I have every single person that came into my life because of that show to thank for that. It's something I will cherish for the rest of my life."
Although Shadowhunters is over, McNamara is still kicking ass but in a different series. She joined the CW's Arrow as Mia Smoak in 2018. The new eighth season premieres on Tuesday, Oct. 15.
If Mia were to get a spin-off, the actress describes she'd like to delve even deeper into her character and push the boundaries.
"It would be nice to see Mia out of her comfort zone in a sense. We see that a little bit this season," McNamara says. "We get to see Mia try and be a part of a team, in which she doesn't necessarily play well with others, at this point. But to force her to grow and to see her humanity a bit more. To see her relationship with her brother, to see her relationship with the other people around her and to see her really try and take her own steps to improving Star City, but doing it her way would be very interesting to see."
McNamara, who started out acting, singing and dancing in theater at age 12, says she has more time to herself now since she said goodbye to playing Clary, turning her attention to her other passion -- music.
"I'm constantly singing. I'm constantly making up songs as I go through my day," says McNamara, whose first single, "Ember," played during the finale of Shadowhunters' second season.
McNamara recalls breaking out into song with her co-stars on set.
"Actually it was a very common occurrence for all of us when we were all in one room to blast Disney songs and or musical theater songs and create an ensemble of sorts in three part harmony. In fact, we still end up doing that when we get together. It's a nice little piece we all carry with us."
"Now that I have a bit more time I'm looking to put some more together, so keep an eye out," she adds.
Watch McNamara's full interview in the video above and watch more episodes of Unfiltered: