Jamie Lynn Spears on Motherhood, Marriage and Overcoming the 'Teen Mom' Label

With her hit Nickelodeon series having just wrapped, Jamie Lynn Spears' star was at its brightest in 2007 – until a positive pregnancy test changed everything.

"It was scary – I couldn't believe it," Spears, now 25, tells PEOPLE of the home test results she received in a BP gas station bathroom.

Sixteen at the time, Spears and her "first love," then-boyfriend Casey Aldridge, kept the baby news under wraps, sharing it with close family in the fall before going public in December 2007.

Like many teenagers, Spears was preoccupied by how her parents would react. "My biggest concern was, 'Oh my goodness, I need to tell my mother and father and my family,'" she says.

The Zoey 101 starlet also felt the pressures of her post as a role model. "I was on a Nickelodeon show, so I felt responsible for what these young girls were gonna think looking up to me," she says. "I put myself in an adult situation, so I needed to handle it like an adult. My age was never an excuse for me."

But Spears felt a greater responsibility to her unborn child. Having been in the public eye since her big sister Britney broke out in the late-'90s, she decided to take a respite from the spotlight and sequestered herself away in her Mississippi home.

"I needed to step away from the noise of the world and just focus on growing up and becoming the best mother," says Spears, now 25, who will share her story in the TLC documentary Jamie Lynn Spears: When the Lights Go Out, airing at 10/9c on June 26.

Spears gave birth to daughter Maddie Briann on June 19, 2008. Then two years later, she and Maddie's dad split.

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"We tried to do the right thing, but it ultimately wasn't the right thing for our forever," says Spears of her split from Aldridge. "It just wasn't the the healthiest situation for any of us. So accepting that and moving forward and working on myself allowed me to be open to finding the right person."

Mr. Right turned out to be businessman Jamie Watson, whom Spears began dating in 2010 after her breakup.

While Spears found love after becoming a mother, she also found her voice – because she became a mother.

"When you have to be strong, not only for yourself but for someone else, you grow a whole other layer of skin," she says. "That strength comes from being a mother."

Shortly after giving birth, Spears reevaluated her career. "As you get older, you're able to say, 'What is the real channel that I want?' And that's where music made the most sense for me.'"

Seeking creative sanctuary in Nashville, Spears discovered a passion for country music working with the songwriting community, calling those formative years "like college for me." Indeed, in 2013, Spears and her sister recorded a country-song, "Chillin' with You," for her sister's eponymous album; a year later, she released her debut EP, The Journey.

Also in 2014, Spears and Watson, 33, said I Do in New Orleans, with daughter Maddie by her side as flower girl.

"She's got such a sweet little heart," says Spears of her daughter, now 8. "I feel like I've raised her with a lot of honesty, but I've also raised her with a lot of love. She's a very happy, content little girl, and there's nothing more a parent could ask for. That's my most proud accomplishment out of anything and always will be."

Even so, Spears acknowledges her daughter has grown up with some perks having a famous mom and aunt: like attending the recent Billboard Music Awards, where Aunt Britney performed a medley of hits and was honored with the Icon Award.

"She's just like any other little kid [would be in that situation]," says Spears. "She's like, 'Hey, am I gonna get to see Fifth Harmony?' or 'Oh my gosh, Ariana Grande is gonna be here!'

"But we keep her really grounded about that," Spears adds. "As long as you remind your kids to be humble and appreciated; that's really important."

As Spears settles into life with a family of three, she has also found major success as a songwriter: Last year, "I Got the Boy," a track she co-wrote for country breakout Jana Kramer, peaked at No. 5 on Billboard's Hot Country Songs chart. Then, in March, she made her debut at the Grand Ole Opry, performing new music, including new single "Sleepover," due Friday.

No matter where her blooming career takes her, though, Spears has her priorities in line.

"When I'm not working, I'm being a mom and a wife," she says. "I hope to be on a big piece of land, surrounded by the people I love, doing what I love."

And these days, what she does largely depends on Maddie's schedule.

"It's a different story every day," she says. "Today we have her softball pictures!"

Eight years after putting her fame on hold, Spears has a has a strong sense of identity and – with her TLC special – is ready to tell the world she's more than Britney Spears' little sister, a one-time child star and a teen mom.

"Most people aren't introduced to the world as a young child; you don't know what they were doing when they were 11," says Spears. "It's the right time to bridge that gap so people who knew me as a young girl now get to meet me as an artist and an adult for the first time."