Alec and Hilaria Baldwin share sons Edu, Romeo Alejandro David, 2½, Leonardo Ángel Charles, 4, and Rafael Thomas, 5½, as well as daughter Carmen Gabriela

Alec and Hilaria Baldwin have welcomed a new addition to the family, a source confirms to PEOPLE.

On Monday, Hilaria shared a photo of their newborn, taken by husband Alec, on Instagram, writing "7" and a red heart emoji. The new addition comes months after Hilaria gave birth to son Eduardo "Edu" Pao Lucas in September 2020.

For more on Alec and Hilaria Baldwin's baby news, listen below to the episode of PEOPLE Every Day!

The couple share sons Edu, Romeo Alejandro David, 2½, Leonardo Ángel Charles, 4, and Rafael Thomas, 5½, plus daughter Carmen Gabriela, 7. Alec is also dad to 25-year-old daughter Ireland.

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Speaking with PEOPLE back in November, Hilaria said that "during times of COVID, it very much feels like we're done" expanding their family. "Everybody's asking me this question. I don't know. I've said in the past that I was done when I wasn't done. I think, right now, I'm so tired," she explained at the time. "And I feel, just with COVID — it's just insanity."

Hilaria also shared that her kids always ask when another sibling will join the family.

"My kids are used to new siblings coming in, so they're already like, 'When is the next one going to come?' " she said with a laugh. "And I'm like, 'Guys, you and the entire world need to stop asking me that!' "

"They've been really great, though. They love [Edu]. They love babies," Hilaria added. "It's actually really amazing to watch them because I know that they're going to be the kind of adults who are really good with kids because they just know so much."