"You look at your baby and think, 'Wow, I did that.' It's really amazing," Sweetin, 26, tells PEOPLE in its new cover story, on sale Friday.
As Zoie happily snoozes on the shoulder of her dad, Sweetin's husband of 10 months Cody Herpin, the marveling mother says, "I'm still like, 'Oh, wow, I'm a mom.' It's the most overwhelming, exciting thing I've ever done."
And a far cry from where she's been.
Best known for playing spunky middle child Stephanie on Full House from age 5 to 13, Sweetin then landed a real-life role that cast her against type: battling an addiction to crystal meth.
At 22, Sweetin was a college student married to LAPD officer Shaun Holguin and taking a break from acting when she first tried the drug. Six months later, she had developed a crippling daily habit that she kept secret from her husband. That is, until in 2005, when she was hospitalized after a night of partying.
Sweetin and Holguin divorced after she left treatment, while she was spending six months in sober living with people from rehab. She met Herpin, a film transportation coordinator, through friends, and the couple began dating in May 2007 – and wed just two months later.
When their whirlwind romance was quickly followed by a pregnancy, says Sweetin, "it was a blessing."
For Sweetin's complete story – including how the support of her new husband and her former TV cast helped with her recovery – pick up this week's PEOPLE, on newsstands Friday
Video: Meet Jodie Sweetin's Baby Girl!