Using photoshop.
1)Use magic tool Bar. (Keytab: W)
a)Under options at top: select (double box) Add to select.
b)set tolerance to 20: Make sure anti-alias, contigous, and sample layers are checked.
c)Highlight all of her white shirt.
2)Now right click on her shirt.
a)Under the opened pop up options select: layer via copy. (you should now have a another picture opened labled:
Layer 1.
3)Under enhance tab: select Auto-levels.
4)Under filters tab: select option: Noise. On the menu pop up select :reduce noise. Set reduce color noise slider to desired level. (Enough to keep the original desired color at the same time reducing the auto levels "Color Noise" effect. (Btw- The Auto-levels didn't add to much color noise. Since you selected a very specific color earlier under the Magic tool bar. Hint: The more colors there are when Auto-leveling, the more the color noise is introduced.)
5)Under enhance menu select: Auto color selection. (The picture should have a red tinge instead of a "blue" tinge.)
6)Now under layers (Bottom right hand corner. Select the forward arrow by opacity. Slide the Bar left-right to achieve the right desired blended effect. (btw: Don't forget to click the box beside the background image. There should be a eye by it.) For the sake of this tutorial I selected opacity 75%. Now left click <More> above opacity. A menu will pop up. Select Merge Visable.
Save pic, post on occ. (Notice there is a lot more that can be done. But for now, This will help to reduce the color noise added by auto-levels.)
Anyway, feel free to post some more. The more you do, the better you get. And perhaps you sometime later can give me a few pointers.