Hilary Duff is a proud new mother and she is sharing her joy with over one million Twitter fans.

The 24-year-old has taken to her Twitter account to post photos of her baby boy, Luca Cruz Comrie. Most recently, the former Disney star posted a family portrait of her holding Luca Cruz with husband Mike Comrie by her side.

The beautiful black and white snapshot shows the couple happy and proud of their new bundle of joy, who is swathed in a blanket while being held in Hilary Duff's arms.

Hilary Duff is already using her new motherhood for good. Big News! I'm working w/ Johnson's Baby on its new charitable program, Johnson's Baby Cares, http://www.facebook.com/johnsonsbaby- I love being a mom :) she tweeted on Thursday. The charitable platform was set up to support maternal and baby health.

The young wife, mother and actress posted the first photos of Luca Cruz on her Twitter page on April 3. Fans were thrilled to get a glimpse of the newborn.

Baby Luca, 2 weeks old :) she tweeted to her 1.1 million followers.

Duff has been tweeting photos of Luca Cruz along with details of her post-baby workout plan.

@AlisiaLeibel holy sore body!!! @soulcycle kicked my booty!!!! Ouchieee, she tweeted after what appeared to be a particularly difficult spin class.

The Daily Mail reported that Hilary Duff has also taken up Piloxing, a new workout described as a program that uniquely mixes Pilates and boxing into a fat torching and muscle sculpting workout guaranteed to whip you into shape.

Just nine days after giving birth, Duff stepped out to get her hair done and flaunted an already-slim physique in West Hollywood.

Fans and friends tweeted to the young beauty, complimenting her post-baby look. @HilaryDuff girl, ur impromptu car self-portrait looks better than my headshots. all of them ever. not surprising given ur face, but still, wrote Duff's friend Aimee Parker. @HilaryDuff and that's my ridiculously stupid way of saying 'you look amazing'. x.

Duff, who gave birth to baby boy Luca Cruz on March 20, looked slim and fantastic in leopard print Current Elliott jeans and Kelsey wedges from the Rachel Zoe Collection.

The former Disney star seems to be quickly adjusting to life as a mother, waking up for 4 a.m. feedings for her baby boy Luca Cruz.

Luca fed! Mamma fed! Time to do it all again in 2 hours! Oh how life has changed! Lol In such a wonderful way :), she tweeted to fans, later adding, 4 am...Sleepy eyed. Feeding baby..whew this job is no joke!

Check out more photos of Hilary Duff's slim post-baby body on the Oh-Hilary fansite.