A 1.2 should do better than this. With a warm engine, zeroing the trip and driving for 20+ miles at a steady 50mph on level ground should get you a trip mpg figure into the '70's. You really need to do this in both directions as wind can easily affect a single trip figure by up to 10mpg.
That said, most of our 1.2 owners driving in a more normal way seem to report somewhere in the mid 40's overall, which is in broad agreement with the real world figures you'll find on honestjohn & fuelly. If you do a lot of short journeys, 40mpg is not a cause for concern.