She couldn't stop her drug use, though, and lost the baby at four months.
"I felt like shit," she said. "I completely lost it ... I was addicted. I felt so ashamed. I still live with shame about it. On a regular basis."
Why did the drug use continue during pregnancy?
"I don't know. I just kept thinking it was all going to be OK. I remember having thoughts of wanting to get my shit together and get sober. But that's the life of an addict. You don't really think things through."
Back home, her boyfriend never stopped drinking. And after her miscarriage, the two became physically abusive to each other. And then she got pregnant again.
For several years, she struggled to raise a child while balancing the life of an addict and college student. She was attending South Central College to become a nurse.
She graduated from SCC in December 2005 with a nursing degree. That was the same year she started using methamphetamine.
"And then I lost control completely," she said. "I started shooting meth. I lost my career. They wouldn't let me anywhere near people ... Lost my nursing license, found out I had hepatitis C. And then I lost the kids."
She'd also begun selling. With connections she made in the drug world, she had ways of getting enough meth to become a dealer.
"I was selling. A lot. Couple grand a day. I'd flip it, go back and get more. Sell it," Herz said.
Her days of selling ended in the parking lot of Super America in North Mankato. A guy she'd been selling to was working as an informant for police. She was arrested and went to drug court. Part of her sentence included mandatory drug treatment, which she said was good for her, but it didn't stick. She slowly crawled back into the meth world. Her kids, meanwhile, were living with their father.