"How do you know if someone is really thinking this way or not," Staver said, adding that Coy is too young to decide on such a different identity. "How do you know if someone just wants to go in the restroom and be a peeping Tom?"
Coy was born a triplet with two sisters and identified as a girl before she began attending elementary school in Fountain-Fort Carson School District 8, an area heavy with military personnel near an Army base. Her father, Jeremy, is an ex-Marine.
At 5 months, she took a pink blanket meant for her sister Lily. Later, she showed little interest in toy cars and boy clothes with pictures of sports, monsters and dinosaurs on them. She refused to leave the house if she had to wear boy clothes. After her parents accepted her identity, they said, Coy come out of her shell.
Coy was diagnosed with "gender identity disorder" — a designation the American Psychiatric Association removed last year from its list of mental ailments. The removal reflected the growing medical consensus that identification as another gender cannot be changed.
The Mathises said they feared the district's decision would stigmatize Coy, who was reduced to tears when her teacher briefly put her in the boys' line. When she came home, according to legal records, she cried to her parents: "Not even my teachers know I'm a girl!" When Coy rose to first grade, the district forbade her from using the girls' restroom.
The Mathises filed their complaint in February. The civil rights board's director, Steven Chavez, found in a legal determination issued June 18 that the district's solution of letting Coy use staff bathrooms smacked of "separate but equal" and clearly violated her rights.