The curvaceous Welsh star was looking a little more svelte than usual at a recent gala benefit dinner in California which was the result of a lot of hard work and some valuable motherly advice.
The Chicago actress has listened to her mother Pat who told her to avoid faddy quick fixes. "Pat told Catherine that when she turned 40 it became harder to shed the pounds, so she urged her daughter to do something now," a source told Grazia. "Catherine trusts her mum more than anyone in the world."
The source added that it is not easy for someone naturally curvy like Catherine to lose weight, but she has been "working her socks off over the last two years to achieve her new figure."
And she is determined to get in shape before she hits 40. Another friend of the family added: "Pat told Catherine that the most crucial body years of any woman's life are the late thirties, because if you get in shape then, it sees you through later life."