Since you just said fill flash, I'm guessing you're using the onboard flash. That being said, there are these little baggie-looking things you can buy that slide over the flash. They're usually made out of a thin white material (mesh or something). And what it does is soften the light.
Since you can't (I'm guessing) go off-camera, I'd say this will be your best bet. Also avoid backgrounds that are far away from the subject when using camera flash. Otherwise your background will be underexposed and sometimes the computer in the camera will overly brighten the subject, thinking, "Alright, this photo has the right amount of light and dark."
Lastly, try adjusting the aperture in the first one to blur the background more (smaller number, like f4 or so). If you have a point-and-shoot, though, this won't work nearly as well. If that's the case what you have is probably your best bet.
By far, I like the second one. Good job if you're using the camera flash. If not, try positioning the flash in other places, and remember to have fun!