Transcript for 'Younger' star Hilary Duff reveals when her son realized she's famous
from Australia back there and we have a great audience. You got to bring out a great guest. Absolutely. It's necessary. We deliver in we do. We'll bring out the very talented singer and actress. We all got to know her as Lizzie Maguire and all grown up starring in "Younger" on TVLAND. Please welcome Hilary duff. Hi. Great to see you. Hi. Welcome. You're looking great, Hillary. Hi. Mwah. Come on back. You know, we've got to start by apologizing to you. Why? We have to -- We just started. I'm looking at the stuff you post on Instagram and Monday mornings are not for you according to what I'm looking at. There you go right there. Nope. Nope. Nope. So how is your Monday going so far? You know what, you guys, I've had enough coffee and I'm good. I'm good. I'm here, excited to be here with you guys. I didn't drink out of my nope cup this morning. I want to ask -- fourth season of "Younger." Congratulations. Hasn't even started yet already picked up for a fifth season. Congratulations. So lucky. Really fun -- I love the premise about a 40-year-old woman who pretends to be 26 to land a job, so many people binge this. Just lover it. What do you think it is about this show that's so addictive? I think there's so many -- such -- like all women can relate. Women of all ages and everybody can relate to wanting to reinvent themselves or feeling stuck or someone is not accepting you. This lie -- and telling a white lie. This is a little white lie that goes on too far and everybody can relate to that. Like and just to get what you want and then it gets really tangly. So -- It's delicious. It is. Delicious. It's the same creator of "Sex and the city." Which Darren star is amazing. Our whole writing team is amazing but he knows how to write for women and I think our show is really the perfect mix of tugging at your heart strings and a little too edgy where you're like, dad, don't watch that episode. You put us right to the edge then you bring us back. It's really a tale about friendship. There is love interests like weaving in and out but it's a tale of friendship between women. Would you all like to see a little clip of "Younger"? Here it is. This is the living room. We split the cable bill. That's the kitchen. There's always combos so help yourselves. And the bedroom. Oh. My bedroom? No, it's a shared bed. We could make a pillow wall if you want. That express sion. I feel your pain. I know. There wasn't enough to witness we lingered a little extra long for you. Yeah. You have a birthday coming up. I do. You do. You're like -- Nope, nope, nope, nope. You should be proud of your birthday. You've earned it. I'm super proud. I'm excited. And your son, when I read this about you, he's 5, right? Yes. He just realized you're Hilary duff. Yes. What was that like? Oh, you know what, he came home from school. I picked him up from school and when he got home, he is like, I know -- I know your name and I was like, I know. And he's like, no, no, your name is Hilary duff and I'm like, caught. Like I didn't know how to respond. I'm like, yeah, that is my name but he said it with a little fwlints in his eye like somebody told him something that I isn't and I'm like, no, I'm not ready for this yet. He's seen me on the cover of a magazine in a grocery store. I think he thinks the next day it's the next mommy's turn. Lizzie Maguire, you recently tweeted about the show. Do you miss it? No. I don't. I don't but I loved it and honestly it prepared me for so much and, you know, I think just like everyone else that it like hit him when they needed it to at that time of their life. It did the same thing for me like I totally related to her -- I felt like I was her completely and I love that she -- Totally worked. She was so relatable but I'm kind of glad to move on. You did have a bit emoji. How good. I posted the other day saw like a meme on the internet. I'm like, I didn't even realize but I had the first bit emoji. I wish I could make mine look like that. Those platfors. And you know what, I know your name. Our birthday is coming up. Any big plan. Yes, so it's the big 3-0. I can't believe I'm 30. I know. You know what, everyone tells me it's amazing so I'm excited and I want to take a girls trip to Europe like all my friends. That sounds so good. Everything. You enjoy it. Thank you. You only turn 30 once. Get it in. And then it's 40. Ah. Season four of "Younger" premieres June 28th on TVLAND.
This transcript has been automatically generated and may not be 100% accurate.