Kitagawa-dono, listed as Soun's older sister in documents from the early Edo Period, married Yoshitada IMAGAWA in 1467, when Soun would have been 36 years old, which would make her marriage too late in her life.
江戸時代前期の史料で姉とされる北川殿が今川義忠と結婚した応仁元年（1467年）で早雲は36歳になっており、姉だと当時の女性としては晩婚に過ぎる。