Here the writer speaks of Athaliah as if she killed the children herself, but the reader should understand that she would have ordered her servants to kill them. Alternate translation: "she commanded her servants to kill all the royal children" (See: [[rc://en/ta/man/translate/figs-metonymy]])
This refers only to the males, because they could become king. Verse 11 confirms that the sons were the ones who were killed. (See: [[rc://en/ta/man/translate/figs-explicit]])
The word "house" is a metonym for the family that lives in the house. In this case, it refers to the kingdom of Judah. Alternate translation: "Judah" or "the kingdom of Judah" (See: [[rc://en/ta/man/translate/figs-metonymy]])