I read this novel in the 1970s when I was in early-mid elementary school. The main character and her family live in a state in the upper Midwest; she’s wicked into competitive figure skating and has been training/competing for years. Because of her dad’s job (he might be a college professor), they move from a city to a more rural part of the state where there are no indoor skating facilities and no training. She checks out the lake where the other kids skate, but finds it unsatisfactory (perhaps the surface is always bumpy). She finds a perfect pond! Ice is always clear of snow and smooth. But the locals shun it. She’s happy to train there alone. Eventually, she learns the reason why the spot is shunned by locals. It was a tragedy. The family that owned the mill was holding a party there for their daughter (about the same age as the novel’s main character), there was a fire, and the girl was killed.