Growing up as the youngest daughter of Wayne, Sr., and Tirrell Van Gelderen, Joanna gained a love for the Lord and His work as she served and traveled with her parents. In 1990 she earned a Masters degree in interpretative speech from Bob Jones University and taught on the collegiate level. In 1992 Joanna married Mark Gillmore, and together they have nine children. Her greatest joy is seeing her children yield their lives to the Lord for gospel ministry worldwide.

Since 2002, Joanna has taught Interpretative Speech at Baptist College of Ministry, including coaching recitalists. Her passion is to see her students use their speech skills in church ministry. Joanna began serving as Dean of Women in 2011. She seeks to challenge and personally communicate with young ladies as they develop biblical convictions that will make them leaders for Christ in their home and future ministry opportunities.

She shares the passion of her husband for world missions and global gospel advance. She relishes every opportunity to travel abroad and encourage believers across cultures. As part of her local ministry, she impacts a number of ladies through one-on-one and small group Bible studies.