0 used to show that the woman or girl who does the action is also the person who is affected by it -- 彼女自身
2 used to show that a particular woman or girl did something -- (彼女が)自分で
We can complete it step by step however long the road is and it can't be completed however short the road is if you don't even mark your footprint.
道路がどれだけ長くても、一歩一歩完了することができますし、足跡をマークしなければ、道路がどんなに短くても完了することはできません。