Members of Jill's family shared birthday messages with her via social media.
Derick was the first to share birthday wishes with Jill Duggar, and he did so via Instagram.
"Happy 24th birthday @jillmdillard You're the best wife and now mother to our little son! I love you baby!" he captioned the photo.
The 19 Kids and Counting parents, Jim Bob and Michelle Duggar, wished Jill Duggar Dillard a happy birthday via the family's official Facebook page.
Jill Duggar was even celebrated for her 24 years on earth on the Duggar Family Blog, where a collage of everything Jill was shared with family members, friends, and fans. They titled the blog post, "Duggar #4 Turns 24."
Jill was born 16 months after Jim Bob and Michelle Duggar had their twins, John and Jana.
"Growing up, people would sometimes guess that Jana, John and I were triplets because we were so close in age, or that Jana and I were twins, since we looked so much alike," Jill Duggar Dillard wrote in her own blog post.
This is the first birthday Jill Duggar has spent as a mom. She and Derick Dillard welcomed Israel David Dillard into their world back on April 6th. Now Jill is likely excited about sharing her knowledge with sister Jessa Duggar Seewald, who is expecting her first baby on November 1st.