Hi Gigi,
I've been following this thread throughout the day. I looked at the original photo large in PS this morning, and gave sort of a sigh...at that time, I spotted some technical faults that made me not want to try and retouch or post process the photo. Also, at that time, the thread seemed to be deteriorating,and I figured it wouldn't really help much. I then went to your blog, to see what your photos and you were "all about".
Here's my comments about the thread and your work. First, I think Sw1tchFX and Bitter and others are trying to tell you that it is always easier to get things right in-camera than it is to take a less than perfect image and try and retouch it. There seems to be shutter speed blur that rendered her hair blurry, so clipping path approaches will be a PITA. If you want a lighter background, shooting in front of a lighter,even-toned background is always,always easier. A background with a color scheme that is NOT found in the subject's clothing or complexion will allow very fast, pretty easy selective color hue shifts in the background using NO clipping paths, but just selective color in Photoshop. For example, if you shot that on black seamless, but lighted the background with a strong blue-colored gel, you could shift the background to yellow or orange-ish or green hues very easily, in seconds, without the need to do a clipping path or any masking...
The idea of digital photography is to work from good source material, or source material that is either 1) ideally or 2) realistically re-touchable or modifiable, without the need to knock one's self out doing it. If the photo had been shot on either a green or blue chroma-key backdrop, and had been rendered crisply with say an electronic flash fired through an umbrella, people could drop in backdrops for you in 1 or 2 minutes, clone out her skin blemishes, create a layer and soften it, then modify the layers (screen, multiply, soft light, whatever) and then merge the layers, flatten, and post up a modified JPEG for you,and it would look fantastic. The problem comes from the way the source file was photographed...it's not meant as a slam, but I know Sw1tchFX's background in studio/commerical photography and what he was telling you is spot-on advice...it's easier, much,much easier to simply do a re-shoot with a,lighter background than it is to re-arrange 3 million pixels after the fact. A quick under-the-chin placement of a white Foam Core board would produce lower-eyeball catchlights that would add shape,sparkle,and dimension and would look "real" and would save a huge amount of retouching effort.
I think you could use a good umbrella and electronic flash and a decent under-chin reflector system to good use with your kid photography. The "quality of light" that a good umbrella would bring would step your photos up several notches.