Kourtney Kardashian pregnant: Sister Kim Kardashian is "thrilled"

(CBS) Kourtney Kardashian broke the news yesterday that she's pregnant with her second child, and her sister Kim Kardashian says the whole family is excited.

"This is such a blessing and the whole family is beyond thrilled!" she shared in a blog post Wednesday.

Pictures: Celebrity baby bumps

Kourtney and boyfriend Scott Disick are already parents to son Mason, who turns 2 this month.

"I just know Mason will make the best big brother and I can't wait to meet my new little niece or nephew!" Kim added.

Khloe Kardashian also shared her excitement at being an aunt twice over.

"Can you believe it?! Masey is going to be a big brother!" she wrote on her blog. "We are all so overjoyed by this wonderful news and are counting down the minutes until we get to meet the newest member of our family. Kourtney is the greatest mom in the world and I am so proud of the woman she has become."

She added, "If this next baby is anything like Mason, then we will truly be the luckiest family in the world."