She said: "I have a date - I'm really excited!"
"I am going to dance around my bedroom and hopefully lose some weight - and lift some weights and do what I can!"
However, the 30-year-old blonde refuses to follow restrictive diets or spend hours in the gym, preferring to tone up in a way that's less demanding.
She explained: "I just have to work out on my own. There is no regimen I need to follow. There's no diet I need to follow. I just need to do some things for myself and that's it. And that will make me feel the happiest."
Jessica is also thinking about what dress she will wear and can't make up her mind which one to choose.
The beauty told Us Weekly magazine: "I'm still trying to figure out what to wear! I don't know if I want the big boom, or the curvy thing, but it will be something beautiful."
Whatever she chooses is likely to be revealing, with the 'Dukes of Hazzard' star recently saying she wants to show off her assets.
Using the French term for neckline, she said: "I have a long neck, so I like to show off my decolletage."