Not a bad effort but I'd recommend trying without the flash - it's created quite harsh shadows. In some photos the shadow of the lens in front of the flash is quite distracting and the paws look like they are nearly blown out whereas your cat is a bit under exposed. Try just using ambient light, and if it's still too dark then try positioning a lamp or 2 near by which won't be as harsh as the on board flash.
Edit: Also if you are trying to get your cats face to be out of focus you probabaly want to use the widest aperture available, your photos were shot at f/6.8, I believe that at the wide end, your lens should open up to f/3.5 which will give more bokeh