Ava McDonald knows something about what many brands want to try to understand: How do you market to Generation Z, the generation of people who were born from 1995 to 2010?

Her answer: You don't. You let them be their most authentic selves and do the marketing for you.

McDonald, who is a 17-year-old junior at St. Stephen's Episcopal School, created Zfluence, a company that connects people ages 16 to 23 to companies that want their brand loyalty. Except Zfluence puts the power in the influencers' hands.

Anyone in that age demographic who has an Instagram account with at least one follower, but not more than 10,000, can sign up to be a Zfluence influencer. McDonald is targeting nano-influencers, which means people who are posting to their unique circle of friends.

"It's quality over quantity," she says, when it comes to the influencers and their posts. Think of McDonald and her friends versus the Lindsay Lohans and Kim Kardashians of the world.

McDonald checks out the nano-influencers who apply and decides whether to approve them. "I want to make sure every influencer we send is quality," she says.

Once approved, influencers can sign up for brands they already use. They will receive gift cards or products from the brand to try out. They get to keep the products and gift cards as long as they post something about those products or what they bought with the gift card on Instagram.

Becoming an influencer for Zfluence started with McDonald's friends, and now it's started to spread to colleges like the University of Texas and the University of Oklahoma and beyond.

"Once someone in a sorority joins Zfluence, we end up getting a lot from that sorority," McDonald says. "Those networks are helping."

There are now 150 influencers talking about 15 brands including clothing lines, restaurants and nonprofit organizations. "It's a good mix of local and national," she says.

These high school and college students, McDonald says, are "people who are passionate about that product. It's all the stuff they would be buying anyway."

McDonald keeps a spreadsheet of all the influencers, which brands they have chosen and their posts. She sometimes has to nudge an influencer to post. "Sometimes life gets in the way," she says.

Brands pay to be part of Zfluence at a starting rate of $50 a month. She plans to donate 5 percent to programs that encourage young entrepreneurs. The brands decide what they want to provide and how many influencers they want to reach. Some want as many influencers as possible. Some want a more personal experience with a few influencers.

Some brands, such as the alcoholic beverage maker Mighty Swell, can be selected only by influencers who are 21 and older. And, yes, McDonald checks driver's licenses. "You can try, but you won't get past us," she says.

She monitors what influencers are posting and what is being asked of them by brands. McDonald has had to train brands to let the influencers use their own voices instead of trying to write posts for them.

She even had to explain it to her mother, Carla McDonald, an entertaining expert and creator of online magazine The Salonniere. "She sees what else is out there," Carla McDonald says. "She looks at this stuff, and she says, 'It's so "cringe."' I didn't see it. 'What about it is cringe?' 'Nobody would say that,' (Ava says)."

For Generation Z, it's all about authenticity. They see through marketing missteps, such as overly written, overthought posts. "It's so obvious when someone is 'trying' to market to Generation Z," Ava McDonald says.

Ava McDonald knows about Generation Z, and she also knows about social media. "I spend more time on social media than the average person," she says.

What she didn't know was how to start a business. That's where her parents came in. For Carla McDonald, it's Salonniere. Father Jack McDonald has made a career of being an entrepreneur. In 2013, he started Upland, a cloud-based software system companies use to manage their work.

"We are super supportive," Carla McDonald says.

Yes, they've given her advice and been a sounding board, but to start Zfluence, Ava used money earned from serving as an assistant at an equity theater company on the East Coast, where she was first a participant.

The idea came in October, and she spent fall and winter developing a website and reaching out to brands before launching in March.

She's doing Zfluence while on the dance team, participating in Model U.N., Quiz Bowl and French Club, volunteering as an English teacher to kids who are refugees, taking spin classes and managing a couple of hours of homework a night.

"Having to balance schoolwork with running a company is really a challenge," she says. "I've learned the value of time."

That means if she has five minutes between classes, she might be answering an email or approving a new influencer. "I see every opportunity as a chance to get something done," she says.

Sometimes Zfluence and school seem to be happening at once, like the time when she got a call from a brand during a physics lab. She had to quickly answer and call the company back.

A lot of work also gets done on the weekend. The weekend is her best friend (along with that spreadsheet), she says.

But when all the emails are sent and the homework is done, Ava likes to sit down to watch "RuPaul's Drag Race" on TV. "It's my guilty pleasure," she says.

Zfluence isn't profitable yet, but Ava McDonald has learned from her parents the importance of investing in the business. In the next five years, she'd like to develop more networks of influencers throughout the country and partner with more brands.

Carla McDonald likens Zfluence to what Bumble did for women on the dating scene, putting the power in their hands.

"It's been rewarding to see her make it her vision and being so committed to what is such a great idea," Carla McDonald says.