I am not a big fan of shooting portrait types of shots with less than 50mm. Wide angle lenses tend to distort the edges a little, as well as push your subjects into the distance.
This shot looks great. Cannot see much of the background, but I am confident it is blurred out.
I agree with Waddizzle's comments - this is working OK for you, don't buy unless you really need it and this does a good job
As Waddizzle and Tronhard this is a great shot! In a case like this it looks like your current lens is doing what you need it to and we would recommend continuing to use it. A wide angle lens could be helpful for getting more of the ballpark in the frame, but as the other replies mentioned the more wide the lens angle the more lens distortion you will start to see. If you used a wider angle lens the subjects in your photos would be smaller in the frame as well, so in cases like this it can be better to use a telephoto lens because your subjects will take up more of the frame.