Robyn Hood Outlaw Princess by John Reynolds

Robyn Howard is a rebellious schoolgirl who, after a violent thunderstorm, time travels to Sherwood Forest where she becomes Robyn Hood the leader of a band of outlaw women. Their main enemy is the cruel Sheriff of Nottingham who rules the area with an iron fist. Robyns encounters include battling against the Sheriffs soldiers, rescuing a princess, finding romance with a young squire, and being captured by the Sheriff. In the Nottingham marketplace she is put on trial and condemned to death. Escape seems impossible - but theres a twist in this YA fantasy tale.