I did it.
It took me about a minute to two, but I tried paying attention to her reflected "left" foot and then perceiving that her toes were facing away from me, not towards. Her reflection started going counter-clockwise, then in my head I went "Holy crap!" and her whole body began to rotate counter-clockwise.

I think I found the trick to getting her to spin counter-clockwise for those who see her spinning clockwise..

It's only going to work briefly, but I've found... well, a Graphical glitch if you will.

Focus on the bottom of the screen, you'll see a reflection. You see her main leg straight, and the foot twirling, but it's the shadow of the outstretched leg that gives it away. Look at the outstretched legs shadow, I see her going clock-wise every time I look at it, but if I look at that outstretched legs shadow, the only way it ever seems to be moving is counter-clockwise, and if you go from looking at that for a few moments and slowly go up, she SHOULD be turning counter-clockwise.

So, start with the shadow, try to look at it on the far left of the screen, then once you see it going around the back, move up to her leg. If she's going clockwise still, look away, or back down. if you see her leg going counter-clockwise then move up to her chest, and space out for a second, it should be going counter-clockwise, you'll then probably think "Woah, she's going counter-clockwise" and then lose it.

1. Kindergarten teacher's hair: Dark and light grey (bonus: Pulled back and tied into bun)
2. Clockwise: 11 rotations until dizziness, Counterclockwise: 12 rotations until dizzness
3. "Reflections" assisted living home in Flagstaff Arizona. (it's not where you plan on going but it's where you'll end up)

In reply to this comment by Kuga:
You're telling me you were specifically wondering what a random Sifter like me thought about Paris Hilton and Britney Spears and the heroine of a cheesy nineties show? o.O

Got any other inexplicably random questions about me bouncing around that head of yours... like what my kindergarten teacher's hair color was, or how many times I can spin around in a circle before getting dizzy, or which retirement home I plan on going to when I'm old?

In reply to this comment by rottenseed:
>> ^Kuga:
What, that I was a teenager during the mid 90's?

Yes.

And that your thoughts on paris hilton and britney spears

and your thoughts on Xena, Warrior Princess...

oddly these are all questions I had about you. Dunno why, just did.

Haa-Pooo!
in Canada twisters spin counter-clockwise.

Cool illusion, but yeah, the left-brain/right-brain thing is BS. Whether you see it going clockwise or counter-clockwise has nothing to do with your brain function, intelligence, inclinations, talents, or whatever. It's just visual perception.

how did you do it. this is driving my crazy

Q

In reply to this comment by gorillaman:
OMG she's going anti-clockwise. Finally.

I see it primarily going clockwise but it has shifted for me....she has more of a wobble when going counter-clockwise.

I starred at the one in swampgirls link.. I can not get it to go clockwise, always CC for me... although I did notice the ballerina has nipples...does that just make me a pervert?

I focus on the foot in the reflection to get it to spin counter clockwise. i can almost view it spinning anyway i want it to.

Deathcow is correct, it's all about vertical perspective. Using the right hand rule with your thumb pointing up her butt then she would be spinning counter-clockwise. If you observe her from the top (thumb pointing down her throat) then she spins clockwise. Really this is just a test of your sexual preference and not brain usage.

WHAT IS HAPPENING TO ME!

At first I could only see clockwise.. Now I can sort of do a blink and see her switch direction (focusing on the top body enforces clockwise, focusing on feet enforces anti clockwise).

In the end she came out and punched me in the face.

The first couple times she was going counter clockwise, and then I stared at her feet till she reversed direction and went clockwise. Now all she goes is clockwise. I can't go back.

What about those of us that see her turning clockwise and then with about 10 seconds left she started turning the other way.

And my co-worker says "I don't know which way she was turning, I was staring at her breasts." I am calling HR right now.

I was able to see her counterclockwise if I looked at the mouse and watched her only with the side view.
Then she stabilized counterclockwise and couldn't turn her clockwise again, lol.

finally! came back for one last attempt and the lady now spins both ways. it was putting her in peripheral vision that did the trick for me, for the record. focusing a little left of the image made her spin anti-clockwise and focusing a little right of the image made her spin clockwise. also became much easier and controllable if i coupled that with the technique for seeing autostereograms where you shift your focus, like you're staring through the page. can't believe how long this took me. i also found the animated picture in the link that's been supplied in the comments much easier to use.