Ashe in-game draws her arrows back with her left hand. As your dominant hand is what you use to draw the bow in archery for better accuracy, this means she's left handed. Fun interesting fact!
Also makes her a mirror of Tryndamere. Since her right arm is locked while drawing the bow and her left arm is doing all the work, her left arm would be a lot stronger than her right arm.
The thing is, Ashe's classic, Sherwood, Freljord and Woad skins all draw the arrow with her right hand. Queen, Amethyst and Marauder all draw with the left. And all of her in-game models draw with the left.
On a side note, left handed people are often more likely to become ambidextrous in real life due to the worlds bias towards right handedness among other things. So Ashe could possibly be ambidextrous and be able to use both arms to draw an arrow effectively, although her left would still likely be stronger.
Since her right arm is locked while drawing the bow and her left arm is doing all the work, her left arm would be a lot stronger than her right arm.
http://i2.kym-cdn.com/photos/images/facebook/000/430/609/3d9.png
Lot's of champions are actually left handed. 
, 
and 
just to name a few.
Yay lefties!
no that just means she draws with her left
Many right handed archers pull with their left
its just wahtever they learned with
Also about the Tryndamere thing.... Archers use both arms simultaneously one to push and one to pull, it makes it much easier to draw a bow back. That being said who knows anything about her bow it might not have any draw weight on it! OH and also lefties kick ass!
She could just be ambidextrous.
He is her hubby
baa its just an illusion, like the dress
