V.1-9 Ahaziah is the grandson of king Jehoshaphat who had made an alliance with the wicked king Ahab (of Israel). Notice how this connection still brought troubles to the kings of Judah.
V.2 It says “daughters” of Omri but in the Hebrew language sometimes “daughter” is used when it is granddaughter, as it is here (See 2 Chron. 21:6).
V.10 When this wicked daughter of Ahab sees that her son has been murdered, she turns and kills all his sons so that she will have full authority.
V.11 The king’s sister however, hides the youngest boy from Athaliah. In this way God’s direct line from David to Christ is unbroken! God, as always, was in control.