Fans were delighted by the news, sharing their messages of congratulations in the comments.
"Congratulations Jen so happy for you guys ❤️," one wrote.
"I knew it!! I could see your bump in your last post! Wonderful news congratulations," remarked another.
"Congratulations 🥳 🔥you are a stunner!" exclaimed a third.
Jen and Jake, who married in 2013, welcomed daughter Frankie Violet Hawkins Wall in October 2019.
However, the model spoke openly in August that year about how she suffered a miscarriage in 2018.
“Last year was such a tough year for Jake and me. It was the toughest year of our lives. I felt like I almost broke and, in fact, it’s still really raw,” she told Stellar magazine. “But Jake was amazing. He let me sit with the pain, feel it and not be OK.”
"I feel so excited and so grateful just to be pregnant and feeling the kicks," she said after confirming she was pregnant. "When we went to see the heartbeat scan for our little girl, it was the most incredible, overwhelming feeling because prior to that we were so scared."