The 31-year-old is expecting her first child with her fiance Eric Johnson and will deliver any day now.
The singer has posted a video showing a look inside her baby shower. The footage on video sharing website Vimeo reveals the extravagant party thrown in her honour.
The party was decked out with lanterns, pink decorations, safety pins and gifts from celebrity guests including Jessica Alba, Ellen Pompeo and her sister Ashlee Simpson who brought along their children.
"Creating a family is the best thing I've done in my life," she wrote under a picture of her and Johnson where she's holding up a small white dress.
Simpson also gushed about her mother Tina Simpson and posted a picture of her nephew.
"I really hope I can be half as good of a mom as mine has been to me," she said. "I can't wait until Bronx meets his new cousin!" Simpson has told Elle magazine she is expecting a daughter.
"I swear, I will croak if she asks me for a pair of Nikes instead of Christian Louboutins!" she recently joked.
Simpson is reportedly spending $US2 million ($A1.94 million) around the time she gives birth to her first child to make sure everything goes smoothly.
According to In Touch she is splashing out $US500,000 on a birthing suite, $US100,000 on food and room service, $US14,500 on a crib and nearly $US70,000 on a private jet for a possible trip back home to Texas.