The 'Sin City: A Dame To Kill For' star - who is currently expecting a baby with her husband Cash Warren - insists she won't be having anymore kids after this one's born.
The mother-of-two - who has Honor, nine, and Haven, six - was asked if she wanted to add to her brood again and she laughed as she insisted this was the "last one".
And Jessica went on to explain how she manages to balance her family life with her work commitments.
She shared: "I think it's the quality of time that you put in at work and how you're fed at work and what you bring home. And also what you let go of when you come home.
"A happy work place actually makes for a healthier person and healthier children. If you work five hours a day but you hate your job, your attitude when you come home and what that imposes on your kids outlook and their life and their relationship with them, it actually really affects it.
"But if you're happy - even if you come home late and you're working long hours - if they see that you're happy and you're in a good mood and you're present with them that's way better than you spending ten hours a day with them in misery."
Jessica encourages her children to eat healthily and thinks the best way to do this is by doing the same yourself as a parent.
She told E! News: "Your kids are just going to really mirror what you do. If you're sitting there chowing on processed food and fake food all the time, and you don't have any healthy options and you're trying to only make then eat differently, they're going to see that you're a hypocrite. So I think it's like walking the walk and not just talking the talk."