There are lots of techniques to right a cat. The most important part is to stop the mast from filling with water. Be absolutely sure that your mast is waterproof (dump it in water and look for air bubbles escaping).
Second, before you try to right it, release both the mainsheet cleat and traveller.
If you are to light to right your boat now, with a common righting line, you need to use the wind to help you. If you have windsurfed, it's a lot like doing a water-start. Send your wife to the bow, so the boat positions itself with the bow 45 degrees to the wind. Lean far out on the righting line, and the wind will come under the sail and help you right the boat (I am able to right our Tornado myself if assisted by the wind this way and the boat is positioned right).
If you still are unable to right your boat, even with help of the wind, you need a solo~right or perhaps a power-pole. You can get a power-pole trought the store on this site. The Solo~right is a mythical product not made anymore, but it would have been perfect for you. Google for "Gary Friesen" and Solo~right, and you can probably find some information about how the Solo~right works.

Please be careful, sailing a catamaran without being able to right it can be quite dangerous!