For the pregnant pop rocker this will be her second child, joining 6-year-old son Bronx from her previous marriage with Fall Out Boy frontman Pete Wentz.
Simpson and the "Hunger Games: Mockingjay" actor tied the knot back in August of this year after a whirlwind year-long relationship. The intimate ceremony took place at his mother Diana Ross' Connecticut estate in the company of family and close friends, like her big sister Jessica Simpson.
Evan Ross spoke briefly about the prospect of children during "The Hunger Games: Mockingjay - Part 1" red carpet premiere, revealing he was totally into it.
"I would like it," Ross told E! News, adding he wanted to rear "as many as possible!"
Congrats to the happy couple as they start their family together.