Jehosheba (יְהוֹשַׁבְעַת) means "YHWH is an oath" in Hebrew. In 2 Kings 11, Jehosheba was the daughter of King Jehoram of Judah and the wife of the high priest Jehoiada — she rescued the infant Joash from his grandmother Athaliah's massacre of the royal family, hiding him in the Temple for six years.
The Davidic dynasty survived because of her courage.
Jehosheba does not currently appear in the US Social Security Administration's top 1,000 girls' names, so we don't publish a US rank or birth count for it. That says nothing about the name's standing elsewhere in the world — only that it sits outside the ranked US data we rely on.
In Pythagorean numerology the letters of Jehosheba reduce to 1, The Leader. This is a traditional interpretive system, not a factual claim about the name.