Katherine Schwarzenegger's Mom Tells Chris Pratt He's Going to 'Have Another Beautiful Family Member'

The Pratts and the Schwarzeneggers can't wait to welcome a new addition to the family!

Chris Pratt and Katherine Schwarzenegger Pratt are expecting their first baby together, PEOPLE confirmed on Saturday, and their loved ones couldn’t be happier.

Her mother, Maria Shriver, and her brother, Patrick Schwarzenegger, spoke with Pratt, 40, for a #HomeTogether Instagram Live chat on Thursday, during which they discussed his Parks and Recreation reunion special, which will raise funds for Feeding America.

Also during the family conversation, Shriver briefly mentioned her daughter's baby on the way after Pratt raved about his in-laws. "I really love what you're doing. This is really fun, and being right here, right now, it's just uncanny, you guys are both just so beautiful. I'm so lucky to have married into such a gorgeous family," the actor told the mother-son pair.

"You're gonna have another beautiful family member," Shriver said in return.

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Axelle/Bauer-Griffin/FilmMagic Katherine Schwarzenegger Pratt and Maria Shriver

Pratt and Schwarzenegger Pratt, 30, began dating in summer 2018 and have been married for about 10 months. This will be the first child for Schwarzenegger Pratt and the second for Pratt, who shares 7½-year-old Jack with ex Anna Faris.

"After they got married, they couldn't wait to grow their family," a source recently told PEOPLE. "Jack will be a great big brother. Katherine always says that he is the sweetest, most caring boy."

RELATED: Chris Pratt Has Been a 'Dream Husband' Doting on Pregnant Katherine Schwarzenegger: Sources

A friend also added: "They can't wait for Jack to have a sibling."

Since the start of their romance, Pratt's son has been an integral part of the couple's relationship, often joining them on ice cream, movie and dinner dates. "Katherine thinks Chris is an amazing dad. She allowed herself to fall in love with Chris quickly because she early on realized that he is a great family guy," said the source. "She loves being an extra mom to Jack."

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RELATED VIDEO: A Look Back on Chris Pratt & Katherine Schwarzenegger's Whirlwind Romance

A Look Back on Chris Pratt & Katherine Schwarzenegger's Whirlwind Romance

The couple, who began dating in the summer of 2018, tied the knot in Montecito, California on Saturday

RELATED: Chris Pratt and Katherine Schwarzenegger Expecting First Child Together

Sources previously told PEOPLE that the newlyweds were excited to “expand their family as soon as possible” following their June 2019 wedding in Montecito, California.

When they were engaged last year, another source said Pratt was instantly welcomed into Schwarzenegger Pratt's family. The pair actually initially hit it off after Shriver introduced them.

“They never had a typical relationship. It very much helped that Chris already knew Maria,” the source said. “They didn’t have to take things slowly because they were getting to know each other’s families. Katherine’s family instantly treated Chris like a family member.”