|Paris Hilton and Kim Kardashian|
An onlooker told TMZ they overheard Paris say, "So happy for her, they are perfect for each other", when a friend broke the news to her while out shopping.
Paris, 31, and Kim, 32, had a rivalry for years due to their very similar career paths and lifestyles, but recently made up and were spotted out together at a friend's party and at an event in Miami.
Meanwhile, Kim's brother Rob - who recently split from Rita Ora - has also voiced his delight at the news, which broke when Kanye called Kim his "baby mamma" live on stage in Atlantic City on Sunday (30.12.12).
Rob enthused: "It's beautiful. It's a blessing. The New Year, we've got another child coming, so that's great. Kim's never had a baby, so it's going to be a beautiful blessing."
He also hinted Kim - who is still legally married to estranged husband Kris Humphries - won't be walking down the aisle with Kanye anytime soon and wants to concentrate on motherhood for the time being.
He said: "No idea, no idea. I'm sure that will come down the road, but right now I'm sure everyone's focusing on just the baby going on right now. I'm sure that's something in the future."