Albert Barnes Commentary 2 Chronicles 11:18

"And Rehoboam took him a wife, Mahalath the daughter of Jerimoth the son of David, [and of] Abihail the daughter of Eliab the son of Jesse;" — 2 Chronicles 11:18 (ASV)

This is probably an extract from the “genealogies” of Iddo (2 Chronicles 12:15).

As Jerimoth is not mentioned among the legitimate sons of David (1 Chronicles 3:1–8; 1 Chronicles 14:4–7), he must have been the child of a concubine.

Abihail was probably the “grand-daughter,” not “daughter,” of Eliab (1 Samuel 16:6; 1 Samuel 17:13; 1 Chronicles 2:13).