Another emotional moment that I love playing every night is the scene before “Back to Before” with Colin Donnell, who plays Father. He and I have been friends since way back, and his wife was Anna in Frozen with me. We are very connected, and Colin is such a fabulous actor. That scene is so exciting from an acting standpoint, because although the macro version of it is the same, our choices each night vary ever so slightly.

I find it incredibly deep to play the moment where Father says, “I love you.” Mother — as we’ve learned over and over in the story — is unable to lie. She can only stand in the truth. She could easily reply, “I love you too,” but she doesn’t quite feel that in the same way that she once did. Instead, she does say, “Be safe.” She still wants the best for him. As a married woman and a mother myself, the stakes of that moment feel enormous to me.

You’ve played several mothers onstage, including Diana in Next to Normal. What did that experience teach you that you still carry into your work today?

Playing Diana changed me massively as an actor. It’s probably the hardest thing I’ve ever done professionally, but also the most satisfying. What I really learned from that role was a sense of abandon on stage. I’m naturally a planner. I like to do my homework and know exactly what I’m doing — and then I get to be free on stage. Diana helped me learn to embrace the mess a little bit more.

Playing a woman with bipolar disorder, who is in active mania, required a certain level of abandon from myself as Caissie. It made me grow, and I’ve brought that to all of my work since. There’s a courage and ferocity I found while playing Diana that I carry with me in Mother.