Given that Jehoiada the priest was 130 years old when he died, and that he died sometime during the reign of King Joash, that means that Jehoiada was born sometime around the end of the United Kingdom and/or the beginning of the Divided Kingdom. If so, he would have seen the reigns of the 8 kings who ruled after King Solomon - Rehoboam, Abijah, Asa, Jehoshaphat, Jehoram, Ahaziah, Athaliah (queen), and Joash. He would have seen years of conflict in the early Divided Kingdom, years of peace when Judah sought the LORD, and years of compromise that resulted in horrible bloodshed when the house of David allied itself with the house of Ahab.
Jehoshabeath, on the other hand, was much younger. Her father was born during the reign of her great-grandfather, King Asa. Her youngest brother seems to have been born during the reign of her grandfather, King Jehoshaphat. I'd venture to guess that she was born around the same time as her brother. This means that she was born somewhere around 70 years after the division of the kingdom, during the period when the house of David and the house of Ahab were allied.
It seems like Jehoshabeath's grandfather wanted to ensure peace by allying with Israel (is that my assumption?), but we see that making friends with sin only brings trouble. Jehoshabeath's uncles were killed by her father (2 Chronicles 21:4). Her father "passed away, to no one's regret" (2 Chronicles 21:20). All but her youngest brother were taken and killed by enemies (2 Chronicles 21:17). Her brother, King Ahaziah, and the sons of her late brothers were killed while away in Israel (2 Chronicles 22:8-9). Her brother King Ahaziah's children were killed by their grandmother (2 Chronicles 22:10). That drama makes me dizzy. What loss in the House of David!
I wonder if Jehoshabeath found comfort in the temple? I wonder what it was like for her to live as the wife of the priest and as a princess in the midst of all that? To think that she took the risk to rescue her nephew even after all of this tragedy must indicate something of her devotion to David's house and to hope in the midst of hopeless times.
And what would it be like to be married to a man who was said to have "done good in Israel, both toward God and His house"? (2 Chronicles 24:15-16, 2 Chronicles 24:2) Was she the mother of Zechariah, son of Jehoiada, the priest and prophet?
Most passages call Jehoiada "the priest." In my quick search, I could only find 2 Chronicles 24:6 where it refers to him as "Jehoiada the chief priest." Does that mean that he was the high priest? I get rather confused when I dabble in the genealogy of the priests.
Timeline: Prophets in the Reigns of Kings of Judah and Israel