One day last year when her daughter, Ainsley, was 9, Tracee Sioux pulled her out of her elementary school in Fort Collins, Colo., and drove her an hour south, to Longmont, in hopes of finding a satisfying reason that Ainsley began growing pubic hair at age 6. Ainsley was the tallest child in her third-grade class. She had a thick, enviable blond-streaked ponytail and big feet, like a puppy’s. The curves of her Levi’s matched her mother’s.


“How was your day?” Tracee asked Ainsley as she climbed in the car.


“Pretty good.”


“What did you do at a recess?”


“I played on the slide with my friends.”


In the back seat, Ainsley wiggled out of her pink parka and looked in her backpack for her Harry Potter book. Over the past three years, Tracee — pretty and well-put-together, wearing a burnt orange blouse that matched her necklace and her bag — had taken Ainsley to see several doctors. They ordered blood tests and bone-age X-rays and turned up nothing unusual. “The doctors always come back with these blank looks on their faces, and then they start redefining what normal is,” Tracee said as we drove down Interstate 25, a ribbon of asphalt that runs close to where the Great Plains bump up against the Rockies. “And I always just sit there thinking, What are you talking about, normal? Who gets pubic hair in first grade?”


Fed up with mainstream physicians, Tracee began pursuing less conventional options. She tried giving Ainsley diindolylmethane, or DIM, a supplement that may or may not help a body balance its hormones. She also started a blog, the Girl Revolution, with a mission to “revolutionize the way we think about, treat and raise girls,” and the accompanying T.G.R. Body line of sunscreens and lotions marketed to tweens and described by Tracee as “natural, organic, craptastic-free products” containing “no estrogens, phytoestrogens, endocrine disrupters.”


None of this stopped Ainsley’s body from maturing ahead of its time. That afternoon, Tracee and Ainsley visited the office of Jared Allomong, an applied kinesiologist. Applied kinesiology is a “healing art” sort of like chiropractic. Practitioners test muscle strength in order to diagnose health problems; it’s a refuge for those skeptical and weary of mainstream medicine.


“So, what brings you here today?” Allomong asked mother and daughter. Tracee stroked Ainsley’s arm and said, wistfully, “Precocious puberty.”


Allomong nodded. “What are the symptoms?”


“Pubic hair, armpit hair, a few pimples around the nose. Some budding.” Tracee gestured with her hands, implying breasts. “The emotional stuff is getting worse, too. Ainsley’s been getting super upset about little things, crying, and she doesn’t know why. I think she’s cycling with me.”


Ainsley closed her eyes, as if to shut out the embarrassment. The ongoing quest to understand why her young body was turning into a woman’s was not one of Ainsley’s favorite pastimes. She preferred torturing her 6-year-old brother and playing school with the neighborhood kids. (Ainsley was always the teacher, and she was very strict.)


“Have you seen Western doctors for this?” Allomong asked.


Tracee laughed. “Yes, many,” she said. “None suggested any course of action. They left us hanging.” She repeated for Allomong what she told me in the car: “They seem to have changed the definition of ‘normal.’ ”


For many parents of early-developing girls, “normal” is a crazy-making word, especially when uttered by a doctor; it implies that the patient, or patient’s mother, should quit being neurotic and accept that not much can be done. Allomong listened intently. He nodded and took notes, asking Tracee detailed questions about her birth-control history and validating her worst fears by mentioning the “extremely high levels” of estrogen-mimicking chemicals in the food and water supply. After about 20 minutes he asked Ainsley to lie on a table. There he performed a lengthy physical exam that involved testing the strength in Ainsley’s arms and legs while she held small glass vials filled with compounds like cortisol, estrogen and sugar. (Kinesiologists believe that weak muscles indicate illness, and that a patient’s muscles will test as weaker when he or she is holding a substance that contributes to health problems.)