They've learned to watch their older daughter for any sign that something's wrong.
She cuts her long, blond hair and dyes it jet black. And they worry.
Her father picks up a book she's been reading, "The Road" by Cormac McCarthy, and skims it for clues.
He notices a highlighted passage: "You forget some things, don't you," it reads. "Yes. You forget what you want to remember and you remember what you want to forget."
Her parents can relate. There's a lot they'd like to forget, too - especially since the day nearly three years ago when their then-15-year-old daughter told them her elementary school band teacher had molested her and other girls.
The teacher, Robert Sperlik Jr., pleaded guilty last year to sexual abuse and kidnapping of more than 20 girls, some as young as 9. Among other things, he told prosecutors that he put rags in the girls' mouths, taped them shut and also bound their hands and feet with duct tape and rope for his own sexual stimulation.
He pretended it was a game, gave the girls candy and told them not to tell.
And for a long time, none of them did.
An extensive Associated Press investigation found that stories like these are all too common. AP reporters in every state and the District of Columbia identified, for actions that ranged from fondling to viewing child pornography to rape.
Though experts who deal with sexual abuse say victims tell the truth more often than not, the ordeal is often worsened when the community around them is drawn in and people take sides. Often, victims and their families face uncooperative administrators, disbelieving neighbors and an agonizing legal journey.
This family in Berwyn, a suburb west of Chicago, understands the emotional toll.
"It's a silent epidemic is what it is," the girl's father says. "People are protecting people who aren't worth protecting. I hope our daughters will have that instilled in them, too - that you report what you know."
The couple - a telecommunications technician and a stay-at-home mom - spoke on the condition that they and their daughter not be identified, so she can try to move on from the nightmare that began in the late 1990s.
But they want to share their story to encourage anyone being abused by an educator to come forward. They also hope school officials will do more to get abusive teachers out of classrooms.
"I thought my children were safest in school," the girl's mother says. "I don't trust anybody now."
Her daughter was a fourth-grader at Pershing Elementary School when Sperlik began teaching her how to play the clarinet.
She liked him. He said nice things about her and played funny games during class, including letting them draw lips on duct tape and put it on their mouths.
Eventually, though, she and two of her friends started to feel uncomfortable with what they described as increasingly creepy behavior.
After attending a school seminar about inappropriate touching in 2001, they wrote a note to the woman who spoke to them.
He "rubs our leg sometimes, rubs our back to feel for a bra," the girl - then age 11 - wrote for herself and her friends. "He comments (to) me about my hair and how nice it looks when it's down, comments to (another female student) on how she dresses and that she should be a model."
"We are afraid to tell our parents," they continued in the note, which made its way to Karen Grindle, the principal at Pershing.
The girls thought it was enough to flag an adult's attention without having to be too explicit.