I agree with LuLu, it doesn't have to stem from abuse etc.
I was abused as a child and i turned out ok and NEVER went through that rebellion stage, i know it does happen but if she skipped her first day of school in grade 3 i think it's more likely a behavioral issue.
I def think it's something she feels she can't control and i hope theres nothing sinister behind it but i think it's something else.