Their sisters were Zeruiah and Abigail. And the three sons of Zeruiah were Abishai, Joab, and Asahel.
Jewish Publication Society of America Version (JPS1917) - 1 Chronicles 2:16 >And their sisters were Zeruiah and Abigail. And the sons of Zeruiah: Abishai, and Joab, and Asahel, three.