First Published: November 9, 2013 12:31 PM EST Credit: Twitter
LOS ANGELES, Calif. -- 
Caption Jessica Simpson gave birth to her second child, son Ace Knute Johnson, just four months ago and the design mogul is already looking svelte!
The 33-year-old mom showed off her trim figure in a new photo posted on Twitter on Friday night.
“Couldn’t stop smiling on set for my new @weightwatchers campaign today! #happy,” she captioned the photo, which shows Jessica in a field, sporting dark skinny jeans, boots and fitted white top.
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Jessica gained 60 pounds while pregnant with her first child, daughter Maxwell Drew, and worked hard to lose the baby weight quickly. However, this time around, the bubbly blonde said becoming a mother made her less focused on appearances.
“My pregnancies (especially my first with Maxwell) were well documented and my struggles with my weight and body image have played out in front of the world,” she wrote in a blog posted on Parents.com last month. “As hard as that has been, the hardest part is to realize that with all the hurtful and harsh criticism from others, I have been the hardest on myself.
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“Raising Maxwell makes me realize that I don’t want her to see me beat myself up for things like food choices or numbers on a scale. I don’t want her to learn anything like that from me,” she continued. “Those things don’t determine who we are and instead make us feel terrible about ourselves. I want to teach her to value herself, listen to herself and tune out the world. I want her to know her value, rather than spending her energy fighting negative voices from within.”
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