As the women entered a sweltering backyard, their postures changed — both pairs of hands clasped before their chests, both smiles grew wider. They flanked 2-year-old birthday girl Emma, who looked like a little Rapunzel with pigtails, and her older sister, Olivia, a little Belle with glasses. They were instant celebrities, holding court with a gaggle of little girls, as well as moms and dads, one of whom wore a crown.

"Hello princesses!" Copeland said in a sing-song voice.

"I think we found our twins," Busby said.

"We had to come meet you on your special day!"

Busby and Copeland work for a Rutland-based company called Pretty Pretty Princess Parties Inc. It's one of many New England businesses that employ performers to play royals from popular fairy tales. They average four to six birthday parties a weekend, charging between $125 to $375.

At a time when many parents search for gender-neutral toys and attempt to moderate their child's obsession with movie and TV characters, princesses seem as popular as ever.

But that doesn't mean they're not changing with the times.

Nicole Murdoch, owner of Pretty Pretty Princess Parties, said parents are asking her to emphasize life lessons and character traits such as courage and strength to balance the typical birthday party "lessons" on how to curtsy, apply makeup, and wave to loyal subjects.

"With two little girls of my own," Murdoch said, "it made me think about the type of roles we're portraying that princesses serve and what we're putting in the minds of girls to look up to."

She once arrived early to a "Frozen"-themed birthday party to counsel the birthday girl about bad dreams. She dressed up as the Snow Queen, while Copeland was the Snow Princess. They presented the little girl with a special embroidered blanket her parents bought so she wouldn't be scared at night.

While dressed as a princess, Murdoch has also talked to kids about bullying and problems with their siblings. Another family asked her to portray a princess saving someone from a castle and to emphasize that girls can do anything boys can do — flipping the old damsel in distress script on its head.

"We try to tell the kids what the most important thing about being a princess is," Murdoch said. "When they yell, 'wearing a dress' or 'living in a castle,' we say no, it's loving yourself, loving others, and having the courage to follow your heart."

And yet, for all the girl-power themes, many of the princess characters are born of centuries old fairy tales — and carry lingering cultural expectations.

A June study out of Brigham Young University found America's Disney princess culture makes young girls less brave and encourages stereotypical gender roles.

"We know that girls who strongly adhere to female gender stereotypes feel like they can't do some things," BYU Family Life professor Sarah M. Coyne said in a press release. "They're not as confident that they can do well in math and science. They don't like getting dirty, so they're less likely to try and experiment with things."

In the BYU study of 198 preschoolers, "more than 61 percent of girls played with princess toys at least once a week, only 4 percent of boys did the same."

Jennifer Ruh Linder, professor of psychology at Linfield College in Oregon and one of the coauthors of the study, emphasized that it's not that princesses are bad. It's all about moderation and how they're portrayed. Princesses should be more than just a pretty face, she said.

"Parents can play an important role in mediating princess culture for their kids," said Rebecca Hains, a media studies professor at Salem State and author of "The Princess Problem."

She worked as a professional birthday party princess for a few months as part of her research.

"As you're watching media, you can point out scenes that fit your family's values, such as, 'I really like how she stands up for herself in that scene.' Or if you see something stereotypical happen, you can talk back to the screen and model critical thinking skills for your child."

Despite these notions, Busby, a graphic designer from Sterling, always wanted to be a Disney princess. As a little girl, she watched "Beauty and the Beast" so many times she broke the VHS tape. She even worked at Disney World in Orlando for a year.

"I've done birthday parties for families who couldn't afford to take their kids to Disney World," Busby said. "I was so glad to do something that gave that experience of happily ever after."

At 2-year-old Emma's princess party, parents watched as the kids sang, danced, paraded, and played games with Busby and Copeland. Most shrugged off any concerns about princesses and the messages they send.

"I was obsessed with He-Man when I was little, which is equally ridiculous gender-wise," said Jason Fenner, 35, of Arlington. "As long as there's variety, they can play princess and doctor."

Fenner's wife, Julie, 35, said they try not to encourage princesses too much with their daughters, Jane, 3, and, Charlotte, 5. But she felt that now and then it was fine.

"I mean, they're little kids," said Peter Genest, 34, Emma and Olivia's dad. "And it's 1,000 times better than the Kardashians."

The princesses sang "Happy Birthday" to Emma over a stack of doughnuts made to look like Rapunzel's tower before leaving. Her mother teared up.

"I mean, I grew up with it too," Amy Genest, 41, said. "I think you just have to let kids have fun with it. To me a princess is the same as a sports figure. A sports figure isn't going to be your little boy's role model. It's yourself or your family. It's the same with the princesses."

Cristela Guerra can be reached at cristela.guerra@globe.com. Follow her on Twitter @CristelaGuerra.