"Jack and I are super excited to share with you all that we are expecting our second baby!" Lisa posted on her blog, Raddest Mom, on Tuesday, Aug. 6. "I am in my second trimester, feeling great & trying not to eat everything in sight."
"We feel so blessed that our family is growing & Pearl will have a little brother or sister to play with," she continued. "It's crazy to think that we will soon be a family of four!"
Pearl is Jack and Lisa's daughter, born in April 2012. Since her birth, Lisa has become something of a "Supermom," a source told Us Weekly last year.
"She made this huge transition from model and party girl, to wife and unbelievably devoted mom!" the insider said of Lisa, whom Jack, 27, married in October 2012 after more than a year of dating. "She started a mommy blog, because she has literally read every book and is becoming a baby expert. She would like to maybe write a book for first-time moms -- it's something she has started thinking about."
Jack's no slouch, either. "He's so good with the baby," sister Kelly told Us in May 2012. "It's unbelievable."