Mandy Moore Shares Her Family's Adorable Costumes as They Celebrate First Halloween with Baby Daughter Lou

Mandy Moore is celebrating her first Halloween as a mom of three.

The This Is Us alum, 40, shared cute flicks of her three kids — sons, August "Gus," 3, and Oscar "Ozzie," 22 months, and baby daughter Louise "Lou," 5 weeks — as they got all dressed up for the holiday.

Sharing photos on her Instagram Stories, Moore posted a picture of Ozzie, who went as a sanitation worker, wearing the signature fluorescent vest. Gus was seen posing on the stairs, wearing a red dragon costume with the hood pulled over his eyes.

Lastly, daughter Lou wore an orange onesie that read, "My First Halloween," with the proud mom writing, "Someone may have spit up right before this pic was taken..."

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Gus was also seen posing with a few friends, including Meghan Trainor's two boys Barry and Riley, as they got ready to go trick-or-treating.

Last month, Moore shared a sweet photo to her Instagram Stories, flaunting Goldsmith's impressive multitasking skills as he took care of Lou. In the snap, the dad of three could be seen focused on his phone in one hand while coddling a sleeping baby Lou in the other.

"Making set lists and holding baby," the actress wrote over the flick. "@taylordawesgoldsmith is a great multitasker.

 The proud mom announced the birth of their first daughter on Instagram on Wednesday, Sept. 25. "Lou is here!" the proud mom shared alongside a black and white photo from the newborn's birth. "Louise Everett Goldsmith arrived happy, healthy, expeditiously and right in time for Virgo season."

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She continued, "She is our absolute dream girl and her big brothers are already as obsessed with her as we are. Endlessly grateful for our family of 5 (and our very own big three) and soaking in every moment of this special time. 💓💓💓."

On Friday, Sept. 27, Moore shared a touching video of Gus' reaction to his new baby sister. The toddler sits on a bed next to Lou, and Moore can be heard asking, "What does she smell like?"

"Smell her head," Gus said. "What does she smell like?" Moore asked again.

"She smells like honey," the toddler responded, bending down to smell his sister's head again and again." Smells like honey," he said again, kissing her head.