The pregnant singer - who is expecting a boy and girl with husband Nick Cannon - will attend the bash at a Beverly Hills hotel on Sunday evening, and it is being hosted by Mariah's publicist Cindi Berger, her manager Louise McNally and Stefano Zagni of Angel Champagne.
According to website TooFAB.com, Mariah and her guests will be treated to some mouth-watering canapes and drinks while the gift registry for the shower includes a $2,000 custom-made bedding set for a crib, a $350 custom-made car seat cover and a $1,200 stuffed giraffe.
It was recently revealed Mariah, 41, had converted an entire section of her home into a nursery for her twins.
A source said: "Mariah and Nick have converted a whole wing of their Beverly Hills house into a luxury nursery.
"Mariah wanted 18-carat gold trim with ivory walls, soft furnishings and walk-in wardrobes full of Petit Tresor designer clothes.
"There's a top-of-the-range sound system and they'll each have diamond-encrusted iPods and a flatscreen TV that comes down from the ceiling."
Among the items the couple have splashed out on for their son and daughter are Chelsea sleigh cribs costing $2,200 each and a Clara changing table, which has a price tag of $2,800, while the nursery will also be furnished with $2,270 Glam Glider chairs for Mariah and Nick and a $1 million sofa.