THIS IS US -- "The Best Washing Machine in the Whole World " Episode 107 -- Pictured: Mandy Moore as Rebecca -- (Photo by: Ron Batzdorff/NBC)Yes, we're well aware that, after we first met her as a teen pop singer and actress, This Is Us," she taken it to a wild extreme, playing her character all the way into her 60s.

Moore, 36, has skyrocketed back into the pop-culture scene with the success of NBC's family drama, in which she plays matriarch Rebecca Pearson, who audiences first met through a steady succession of flashbacks documenting the early days of starting her uniquely assembled family alongside husband Jack (Milo Ventimiglia), juxtaposed alongside the contemporary daily dramas of their three children, Kate (Chrissy Metz), Kevin (Justin Hartley), and Randall (Sterling K. Brown).

But Rebecca also recently made her first debut in the present day as a well-preserved sexagenarian interacting with her kids and grandchildren -- and with not-so-subtle nods to a currently strained relationship with Kate. Moore gave Moviefone some inside dish on her behind-the-scenes aging process, as well as a hint that a big reveal about Rebecca and Kate's conflict may be imminent -- oh, yeah, and she's incredibly stoked to be singing on the show, too.

Moviefone: I was so impressed with the old-age makeup when we finally saw Rebecca in the present day. But I'm sure that that's a mixed blessing for you. Tell me about the experience.

Mandy Moore: It's a lot of work on my skin. It's really harsh on my skin. I just went through two days of it. I'm so grateful for this job. I love the opportunity to work with what I think is such an incredibly strong ensemble on television. And the opportunity to play this character from 27 to 66 is like, when other time, when else am I ever going to have this kind of opportunity in my career? So I'm totally find to sit down for four hours to put that makeup on.

Tell me about the physicality of playing her at that age. What do you do in your head to get there?

I really think about where she is in her life, and the wisdom and clarity that comes with age. The sort of grounded-ness, keeping in mind the nurturing aspect, the maternal aspect of being a mother and a grandmother, but also where she is at this phase in her life. She's raised her kids. I think there is a sense of like, not like "I don't give a f*ck" that comes with age, but a little bit of like, I know who I am, I make no apologies for it, I'm a strong woman, I raised these kids, I know what I want from my life.

So thinking about that kind of mama bear, empowered woman is something that I try and keep in mind, and then the physicality of it is like, she's 66, she's not 86. She's vital and vibrant and kind of in the most exciting phase of her life, I think. So, maybe her body doesn't move as quick as it used to. Maybe there's a little arthritis in her hand, but other than that, there's not a lot stopping her.

She's got a little friction with Kate, we've learned. So give me a little tease as to what's ahead: Are we going to get to the bottom of that soon, or are we going to have to wait to learn the cause?

We're going to wait, because I don't think even we have all the answers. Chrissy and I, we just worked together, really, for the first time not that long ago, and before we shot those scenes we talked about how we've gotten to where we are, what we think sort of came in between us.

And although [series creator] Dan Fogelman is really great about having this over-arching idea and trajectory of what happens in these milestone moments for the family, he doesn't have all the answers, or at least he hasn't given us all the answers. I think he gives us a little bit of leeway to come up with stuff ourselves. So, hopefully, what we've sort of surmised is going to be in line with the writers.

But I think there's been a tricky sort of amount of friction with them. And I think some things have already been revealed, like Randall and Rebecca are very, very close, and that's got to be hard to feel like there is a favorite child, and for the other two siblings to feel like they're kind of chopped liver, to a certain extent. It's messy, it's life, it's something we all can relate to.

When did they tell you that you were going to be able to sing on the show, and what did that mean to you?

Dan told me pretty early on that there was music in my character's backstory, and that was some way in how Milo met me, that I was singing and that I was in a bar, and he heard me sing. And so I knew fairly early on that like that was going to be a part of the story. I didn't know when it was going to factor in, because he sort of peppered us with all of this wealth of information: This is who you are, this where you guys are going, this is what happens to your marriage, and you're like, "Ah..." Trying to take everything in and trying to remember everything.

But I'm so happy that it's sort of activated that part of me again, and I'm honored to get to share the show with Chrissy and her beautiful voice. I remember everybody was like, "Oh yeah, Chrissy sings, too." I was like, "Oh, that's nice, that's cool. I can't wait to see that episode," and then I'm like, "Holy cow -- it's unbelievable!" But, I love that, again, we're able to have that sort of connective tissue, as well, and that's something that our characters have that we love about each other.

What are you loving about the '70s vibe that you get to live in from time to time?

I love the carefree aspects. I love that it's kind of the least amount of time in hair and makeup. You just slap on some hair extensions and a little bit of makeup, and we go. It's more fun. Because, obviously, as the show goes further along and we go deeper into the '80s, that means I get to wear some real mom jeans, and the fashion is not as fun or as forgiving in the '80s.

"This Is Us" airs Tuesdays on NBC.