The news report posted says she attended a private school in Wisconsin, but it does not specify where that school was.
"Sophia went to a private school in Wisconsin. After she violated the school's internet-usage policy, the family decided she would not return to the school this past fall, according to her mom.
The first time Day took Sophia from her Wisconsin home, Sophia was in contact with her family, texting and calling them frequently. She told them she was staying with friends in Beaver Dam, Leah Franklin said. Because she was no longer attending the private school, Sophia asked her parents if she could enroll in a homeschooling program in Wisconsin.
They agreed, hoping it would "appease her" and help in their efforts to get her home, Leah Franklin said."
I'd note that she seems to have been claiming she was enrolled in a homeschooling program in Wisconsin, but was not being homeschooled by her parents. This could actually be the time she was actually in Arkansas with Day, but claimed she was working at McDonalds near her home and living with a friend.
Why her parents didn't go check on her living arrangements is puzzling.