That's the common theory, especially since she had full sleeves done in that time, but the amount of time she's gone doesn't make sense, so being a future version of herself makes more sense, skylar from 3-6 months ahead, something like that.
Also the principal "did something" to a girl the week prior before she beats him with the bat, and she texted for help.
So my understanding is they kidnapped her, allies helped her escape and either she needs to keep it quiet from the MC or doesn't know he's also involved.