'She just loved the name and thought it was so sweet, ' the insider explained, noting that Birdie is a family name.
Instead of showing off her "glow up", or incredible transformation, the 38-year-old pregnant singer and actress took the opportunity to show off the transformation her body has undergone since becoming pregnant with her third child.
While celebrating her impending due date with a baby shower over the weekend, photos from the party gave away a big clue as to what Simpson will probably be naming her little bundle of joy.
She captioned the photo, "Birdie's Nest", alongside two green heart emojis.
Simpson won't be the first celebrity to name her daughter Birdie - Busy Philipps and Brie Bella gave the same name to their daughters.
Jessica and Eric are also the parents of Ace and Maxwell. "Please don't name the girl Birdie", one commenter pleaded, while another questioned whether or not the moniker would have "a negative effect on a kid long-term". "Feel free to add a couple drops of lavender, rose, rosemary, or wintergreen essential oil", one person advised. "Choosing a name for a child must be hard enough without insensitive people slating it". "I'm always calling my little girl "Birdie.' If people can't say anything kind then they shouldn't say anything at all".
Of course, Jessica's fans came to her defense, pointing out that she can choose any name in the book.
Get push notifications with news, features and more. The entertainer is already the mother to Maxwell and five-year-old Ace.