i'm a hair stylist, shorter hair the better with a small face. also you have to consider the thickness of your hair and the texture; curly or straight. it makes the difference in the cut. and if its a wash and go or styling it everyday hair style. if you really want and like it go for it.
maybe don't cut the fringe? I don't know, Rachel Mcadams kind of pulls it off, but I think just to experiment, try clipping your long hair up for a few weeks and see if you like it short. If you do, then cut it but not the fringe. And if you still want the fringe after a few weeks of having the short cut then go for it. I just looked at your picture and I think you'd look really cute with this hairstyle, but it's such a drastic change, you need to make sure you won't regret it. :)