Wait. Let’s just be real for a second. If you’ve been following the messy, emotional rollercoaster of the Cousins Beach crew, you know that time in Jenny Han’s world doesn’t always move at a predictable pace. We’ve watched Isabel "Belly" Conklin go from a self-conscious kid in glasses to a girl caught in the world’s most stressful love triangle. Now that the cameras are rolling on the third installment of the Prime Video hit, the big question on everyone’s mind—besides whether she picks Conrad or Jeremiah—is just how much time has passed. So, how old is Belly in Season 3?
She’s nineteen. Mostly.
It sounds simple, but it’s actually kind of a big deal for the plot. In the first season, she was fifteen, turning sixteen. By the end of the second season, she was finishing up her junior year and heading into her senior year of high school at seventeen. But Season 3 changes the game entirely. Because the show is heavily based on the third book in the trilogy, We’ll Always Have Summer, we are looking at a significant time jump. We are leaving the high school hallways behind.
The Time Jump: Why the Age Shift Matters
The third season is set roughly two years after the events of the Season 2 finale. This isn't just a random choice by the writers; it’s a structural necessity to get the characters to a place where their decisions actually have weight.
Belly is now a college student. Specifically, she's finishing her sophomore year at Finch College.
Think about that for a minute. When we last saw her, she was choosing Jeremiah while Taylor Swift’s "August" probably played in someone’s head. She was a kid. Now, she’s a young woman navigating life away from her mother’s house. This shift to being nineteen or twenty years old completely alters the stakes of her relationship with the Fisher boys. It’s no longer about who is going to take her to prom or who she’s going to sit with at a bonfire. It’s about the future. Real-life, scary, adult future stuff.
The age gap between her and the brothers remains the same, of course. Steven and Conrad are still older, likely finishing up their college careers or starting the "real world." This puts Belly in a position where she is finally on somewhat equal footing with them, at least legally and academically. She’s not the "little kid" anymore. She’s an adult making adult mistakes.
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Breaking Down the Timeline From 15 to 19
Let’s trace the math because Jenny Han is actually pretty meticulous about the seasons.
In the debut season, everything centered around that "turning sixteen" milestone. It was her debutante era. She was fifteen when she arrived at the beach house and celebrated her sixteenth birthday during the stay. It felt like that classic, shimmering bridge between childhood and whatever comes next.
Season 2 picked up about a year later. Belly was seventeen. The vibe was significantly darker. We dealt with the aftermath of Susannah’s death and the reality of grief. She was a high school junior/senior, dealing with the fallout of her breakup with Conrad.
Now, for the third season, the jump to nineteen is jarring but necessary. Most of the plot in the third book revolves around Belly and Jeremiah being in a serious, two-year relationship during college. You can't tell that story if she's still eighteen. You need that "sophomore year of college" energy where you think you know everything but actually know nothing.
Lola Tung, the actress playing Belly, was born in 2002. By the time Season 3 hits screens in 2025 or 2026, she’ll be in her early twenties. This actually works out perfectly. Unlike some teen shows where a thirty-year-old is playing a freshman, the gap between Lola’s real age and Belly’s fictional age is narrowing. It adds a layer of grounded realism to the performance. You can see the maturity in her face. The way she carries herself is different now.
Is Season 3 Following the Book Exactly?
Kinda.
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Jenny Han is the showrunner, so she stays close to the heart of her source material, but she isn't afraid to modernize things. In the book We’ll Always Have Summer, Belly is definitely nineteen going on twenty. The core conflict involves a massive life decision—a wedding, to be blunt—that Jeremiah and Belly jump into.
Fans have been debating if the show will keep the marriage plotline. It’s controversial. Some people think nineteen is way too young for that kind of storyline in 2026. Others argue that the whole point of the story is the impulsiveness of that age. When you’re nineteen, you’re old enough to sign the papers but often too young to understand the "forever" part of them.
If the show stays true to the 19-year-old age range, we are going to see a much more independent Belly. She’s not just Laurel’s daughter or the boys’ childhood friend. She’s an individual. She has college friends. she has a life at Finch that doesn't involve Cousins Beach.
The "Age" of the Fisher Boys
To understand Belly's maturity, you have to look at the guys.
Conrad Fisher is roughly twond a half years older than Belly. In Season 3, this puts him at twenty-one or twenty-two. He’s likely graduating from Brown (or wherever the show has him finishing his pre-med track) and looking toward med school. That’s a massive gap in terms of "life stages." A twenty-two-year-old man looking at a decade of medical training is in a very different headspace than a nineteen-year-old college sophomore.
Jeremiah is closer to her age, usually cited as being about a year older. At twenty, he’s right there with her in the college trenches. This is why their bond in the third book feels so tight; they are experiencing the "newness" of adulthood at the exact same time. They are both at Finch. They see each other every day.
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Why the Age Jump is a Genius Move
- It avoids the "High School Forever" trope. We don't need to see Belly struggling with SATs anymore.
- The Romance is Steamier. Let's be honest, the show is on Prime Video. As the characters age into their twenties, the romance can feel more "adult" without feeling out of place.
- Emotional Complexity. Grief at sixteen is different than grief at nineteen. The way they handle the memory of Susannah will have changed. It’s no longer an open wound; it’s a scar.
What to Expect From a 19-Year-Old Belly
Expect mistakes. Lots of them.
The beauty of the "Summer" series isn't that Belly is perfect. It's that she’s frequently a mess. At nineteen, those messes have bigger consequences. If she breaks a heart now, it isn't just a summer fling ending; it's a long-term commitment falling apart.
We’ll likely see her navigating sorority life (as teased in the books), managing a different kind of social pressure, and trying to figure out if the girl who loved Conrad at fifteen is the same person she is now.
It’s about the "Turning Pretty" part of the title finally concluding. It’s not about looks; it’s about the internal evolution. The "Pretty" is the maturity. The season will likely cover her nineteenth year and possibly end with a glimpse even further into the future, as the book does with an epilogue.
The Verdict on the Timeline
If you're watching Season 3 and wondering why everyone looks so much more "grown," it's because they are. The leap from seventeen to nineteen is one of the biggest transitions in a person's life. It’s the move from being a legal minor to being someone who can vote, sue, and get married.
Belly is nineteen. She’s a sophomore in college. She’s done with the "Belly" of the past and is trying to figure out who Isabel is.
Keep an eye on the small details in the background of her dorm room or her clothes. The costume department usually drops hints about her age through her style—moving away from the fast-fashion "teen" looks and into something a bit more curated and adult.
Key Takeaways for Fans
- Current Age: 19 years old.
- Academic Status: Sophomore at Finch College.
- Timeline Gap: Roughly two years after the end of Season 2.
- The Core Conflict: Navigating a serious adult relationship with Jeremiah while Conrad re-enters the picture.
If you want to prepare for the emotional damage Season 3 is surely going to inflict, go back and re-read the third book. It’ll give you a roadmap for exactly how that 19-year-old mindset drives the plot toward its final, inevitable conclusion. Just grab some tissues first. You’re gonna need ‘em.