I'm sure other drivers and 18 wheelers are prepared to stop as well when that happens.Brake squeal happens when the rotor's get a glaze on them. Tell her to take it on a highway and get going about 60-80km/hr (No idea what that is in miles) and slam on the brakes, the heat will take all the glaze off the rotors. It's pretty normal, and especially if she isn't applying the brakes very often or she brakes really lightly. The dealership you talked to is full of morons if they say it's from applying the brakes too heavily. I work at a dealership, and even I KNOW this!!