I know that the Church teaches the so-called brothers of Jesus aren’t Mary’s children, but, instead may be Jesus’ cousin since there were no such word at that time as “cousin” they often used the word “brother” to also replace “cousin.” But we all know from Scripture that Elizabeth is referred to as Mary’s cousin. Why wasn’t the scripture clear enough to address the so-called Jesus’ brothers as his “cousins?”
Elizabeth is designated as a “kinswoman” (relative) of Mary in Luke 1:36. They are commonly said to have been cousins because there is indication that their mothers were sisters. The Catholic Encyclopedia explains, “[W]hat their actual relationship was, is unknown. St. Hippolytus… explains that Sobe and Anna, their mothers, were sisters”.