Elaine Disney fits high school between practicing for piano competitions and traveling from Roseburg to Eugene for lessons. This would be trickier if Disney, 15, were expected to be in a classroom all day. Instead, all she needs is a computer with Internet access. The Melrose resident is starting her sophomore year of high school with the online Insight School of Oregon. She’s part of a growing group of students attending public school over the Internet, according to Oregon online schools and Douglas County district officials. A big advantage is the freedom, Disney said. “You can go at your own …