Charles Ellicott Commentary 2 Chronicles 11:20

"And after her he took Maacah the daughter of Absalom; and she bare him Abijah, and Attai, and Ziza, and Shelomith." — 2 Chronicles 11:20 (ASV)

Maachah the daughter of Absalom — that is, granddaughter, as appears from 2 Samuel 14:27, where Tamar is named as the one daughter of Absalom. Josephus says Maachah was daughter of Tamar (Antiquities 8:10, 1). (Compare 2 Samuel 18:18; 2 Chronicles 13:2; 1 Kings 15:10.)

Which bare him Abijah. —Rehoboam’s successor, called “Abijam” in Kings. The other three are unknown.