It might look like your average mother-daughter shopping trip, but for 9-year-old Riley Robinson, this is certainly not a typical back-to-school run. Robinson is about to meet with her personal stylist.
Meet Mona Sharaf, a fashion consultant with some pint-sized clients.
"My first few years, I didn't really see many kids or any kids. And then all of a sudden, my phone was blowing up with kids themselves, calling me -- their parents calling me," Sharaf told "Nightline."
Kids fashion is a huge industry, and the luxury market for children is growing. Stylists like Sharaf, and services like Rent the Runway, tap into an expanding retail space.
"Of all the children's clothing businesses, luxury is one of the groups that's growing the fastest," said ABC News' Chief Business, Technology & Economics Correspondent Rebecca Jarvis.
Watch the full story on "Nightline" TONIGHT at 12:35 a.m. ET on ABC
"Overall, children's clothing does about $233 billion in sales annually -- the luxury market does about $6 billion and it's growing," Jarvis added.
Sharaf has been in the fashion industry now for six years, but it wasn't until recently she started taking on what she calls her "little clients."
"My first client [was a] 10-year-old boy. His mother called me and said, 'I need you to help me make my son dress younger.' And I'm like, 'Younger? He's 10.' She's like, 'Yes, my son likes to wear suits and like suits to school,'" Sharaf remembered.
So, she said she "geared him toward more casual looks." "At 10, they already have their own personality and their own style figured out. So I only got as far as I could."
Soon, more clients were pouring in. She estimates that 20% of her clients are now children and teens.
"I feel like it's just this trend now that blew up," she said. "I was shocked. I never marketed to this group of kids because you know, their sizes change. How long are they wearing it? Not long. So is it worth it to pay my fee to pay for all these clothes when they're going to grow out of it so soon?"
A personal stylist for a child or teen is an extravagant cost. Sharaf charges around $200 an hour per session. But she says it's all about the confidence the right wardrobe can inspire.
"It's a different world. Kids make their own decisions. They're well-informed and they want that same confidence an adult has," she explained. "Their wardrobe is a stepping stone to that. When you're confident with how you look, everything else becomes so much easier -- like you're not thinking about how you look anymore. Their posture changes. It's amazing. You put on a good outfit and you can read the body language."
For Sharaf's clients, that confidence is well worth the cost.
Andrew Lilly, one of her clients, is getting ready to head off to college this fall.
"My mom offered -- she suggested it. … I kind of wanted to get a new look [to] sort of say like … 'I'm actually … starting to care more about how I look,'" Lilly told "Nightline." "[I'm] tak[ing] more pride in my appearance."
Sharaf says styling kids is different from styling adults.
"They are much trendier than adults. They can wear trends and may not look silly. They start the trends," she said.
Sharaf encourages her young clients to get their clothes to fit just right by investing in a tailor. She said one of the biggest faux pas for kids is "wearing clothes that don't fit them -- so like pants, they're all scrunchy at the bottom."
"The better the tailoring, the taller you will appear. ... Tailoring is really important when you're not so tall, because bad tailoring makes you look shorter," she said. "We wear 20% of our closet 80% of the time -- so that's true for kids. You're saving a lot of mistakes. ... So yes, it does save money."
The landscape of the children's clothing industry is changing. Many big-name brands have shuttered their doors, and places that were once mainstays for back-to-school shopping have fallen on hard times. Alternative retailers have rushed to fill the void.
"In retail, we have a really interesting phenomenon happening -- all these old retailers that have been around for years, like Gymboree and The Children's Place, are closing or going bankrupt, or shutting locations. Meanwhile, we have all these new players known as 'digital first,'" Jarvis explained. "They started out only on the internet, you could only access them through apps and websites. [Now] they are building out store fronts ... because of Instagram, because of millennials, [these businesses] are doing quite well."
Retail startups like Rent the Runway are now seeing an opportunity to expand their client base.
"We're actually seeing such positive traction in our kids business. And it's the reason why we have quadrupled our inventory for the fall," Sarah Tam, Rent the Runway's chief marketing officer, told "Nightline."
The popular app, which began with formal wear rentals, is now offering a children's selection -- a natural addition for the rental service.
"Because they're constantly growing, to be able to rent an item that your child will only wear once or twice is actually smart and sustainable as well," Tam said.
"To have items that you're going to spend a lot of money on just for your child to wear once or twice -- it's pretty wasteful," she said. "You can access four items at any given time and it's so much better than spending hundreds of dollars on an item of clothes that your child is going to outgrow very quickly."
These start-up services are providing a new generation of shoppers with a modern way to shop.
"The thing about mill[ennials] and Gen Z becoming parents is that they are waiting longer and having fewer kids, which means they have more disposable income, they also have phones in their hands," Jarvis said. "That keeping up with the Joneses on Insta[gram] is actually driving retail trends."
"Kids now are different than kids of the past. They are armed with information," Sharaf said. "They don't want to go shopping with their parents. Kids don't listen to parents the way they used to and that's like my big takeaway from this. Parents love me … their bonds get stronger because there's less fighting over things like clothes."