I'm weary of saying there is anything "wrong" with it. Some people have taken this the wrong way recently. It is a perfectly nice snapshot type photo.
I can tell you what I think could have been done better.
You have a dead center composition, although there are situation where that works, this is not one of them. It's a common pitfall of new photographers to have everything dead center. I would suggest you learn about the "rule of thirds" as guide (not law) for better composition.
It would help to fill the frame more. Get in much closer, try to eliminate unnecessary detail that has little to do with your subject. I would have opted to have the feet of the children out of the frame same with allot of the pots.
Try to get on the same level as your subject. Seems like you are shooting from higher up.
I don't know if you have a SLR or not, but try to shoot with a wider aperture (small f numbers) to blur the background a little more and isolate your subject, unless you are trying to have the flowers as part of the composition.
1) A larger apeture to throw some of the background out of focus
2) A relatively tight square crop around the people. I disagree with Remi; I'd include the feet.
3) The contrast and saturation could use a boost.
This would be closer to the framing I'd chose for a portrait like this one. The one thing that immediately jumped out at me in the original was the orange-colored bird. I think it really drew attention away from the rest of the image so I cloned it out in PS7. I also applied levels and curve layers to help with the contrast and overall color. There was also a small amount of sharpening applied. In the framing, I didn't mind cropping off feet but I left the girl's because I thought the way she had them positioned brought out some of her personality. I also fixed her missing bottom teeth and cloned out some of the distracting elements in the background.
Well your family(i assume) looks perfectly fine, and the background looks perfectly fine,e xcept that the back and foreground look more interesting. Also their jeans.
Why is that?? The thing is because their upper halfs look brighter than the rest of the pictures, it looks that their faces are pale, pale is not interesting, while it seems to me that the rest have vivid colors.
Also having everything in focus, is not helping mainly because in addition that the background looks like having more correct colors, and more attractive(specially that orange toy/bird in the BG). So that's my opinion.
Other than that family photos are great to be hung on a wall, or put in a frame besides your bed...You have a wonderful one!
Of course mostly no one will notice there is something wrong when you put it in a frame, except for a few picky people, on the contrary...