Hi Jaimie,
I love simple portraits like this. The quiet moments in a young person’s life when, for just a few moments, you get to see beyond the rowdy, chaotic little person kids can be for 99 percent of the time!
There are several things working in your favour with this image; one is the soft light which is providing even illumination over the scene. It's working well for you in this instance.
The composition is also strong. Some people might give you a difficult time about using the timber framing to (in effect) cut the picture into quarters, but the placement of your daughter 'on the thirds' is a nice counter balance to this.
I'm not too sure that I like the string hanging across her face, but given that she's holding the string with her fingers, you could say that it all “ties in”. (Yes, groan now if you want to!).
The one small touch that I think could make this image stronger is a slight tweak to the geometry.
As you look at this image you get the feeling the horizontal rail is rising slightly in the left-hand side of the picture while the vertical rail is tilting to the left slightly to meet it.
One trick I learned several years ago was to go into the Layers panel of Photoshop and then double click on the Background Layer. A dialogue box comes up asking you to create a new layer, at which point you click OK. Now what you can do now is to go to Edit in the menu bar and then click on Free Transform (or you can simply go Control-T (PC) or Command-T (Mac), depending on the computer you're using.)
At this point you will see the Free Transform box appear. Now, if you click on the corners while holding down the Control key on your PC or the Command key on a Mac you will discover you can move that one corner independently of the rest of the picture, and tweak the geometry. In the example below, all I did was to select the top right-hand corner and drag it upwards and outwards slightly so that the two rails become more horizontal and vertical.
Making this adjustment by eye can be difficult, so one additional trick is to turn on the Rulers around the display (Control-R or Command-R) and then click your mouse onto the rulers and drag in some guides. This will make sure you get everything square.
The only other thing I've done to the image below was to add a slight vignette to the picture, although I offset it toward the girl a slight amount. Otherwise, good effort.
Cheers,
Anthony
Image Doctor's edited version