Kaley Cuoco is expanding her family once again. The Big Bang Theory star announced that she and actor Tom Pelphrey are expecting their second child together. The couple shared the news on Instagram with a series of family photos and videos, including a gender-reveal cake that showed they're having another daughter. Cuoco and Pelphrey are already parents to 3-year-old daughter Matilda, and Cuoco said the new baby will be "completing our little family." She admitted that this pregnancy has been a little more challenging than the first, but said the couple is incredibly grateful and excited to welcome "little sissy" to the family. The post included photos of Cuoco's growing baby bump, Pelphrey admiring an ultrasound, and a sonogram image that Cuoco jokingly said appeared to show their unborn daughter giving the family the middle finger. The couple, who began dating in 2022, welcomed daughter Matilda in March 2023. Cuoco has previously revealed that she and Pelphrey picked the name Matilda during one of their very first dates, long before they even had children.