Q. I recently heard that the most mentioned woman in Tanach is Tzeruiya, the mother of Yoav and Avishay. Why were they named after their mother?
A. Indeed, Zeruia was Yoav's mother as is recorded in Shmuel II, 17: 25. Also in Divrei Hayomim I, 2: 16; "and the sons of, Zeruiah: Abishai, and Joab and Asahel, three". The name of their father was Seraiah, as mentioned in Divrei Hayomim I, 4: 14; "Seraiah begot Yoav".
Shaarey Teshuva Lageonim (19, quoted in Ginzei Yerushalaim p.184) mentions that Rav Hai Gaon explained why Abishai, and Yoav and Asahel were named a after their mother Zeruiah; it was in their honor, since she was the sister of King David (Divrei Hayomim I, 2: 16.).
Incidentally, Zeruya is mentioned twenty five times in Tanach, while Esther is written fifty five times.
Rabbi A. Bartfeld as advised by Horav Shlomo Miller Shlit"a
It is unlikely that the Seraiah mentioned in Divrei Hayamim was the father of Yoav, the son of Tsruiah and the nephew of David HaMelech insofar as this Yoav is the son of the Seraiah whose brother, Othniel, was the nephew of Caleb who lived centuries earlier. 1 Chronicles 4:13, Joshua 15:17.