Дитя хоть и криво, да отцу-матери мило

Parents are partial to their children. See Всяк кулик свое болото хвалит (B)

Var.: Всякому своё дитя милее. Своё дитя и горбато, да мило

Cf: All one's geese are swans (Am., Br.). The crow thinks her own bird fairest (Br.). The crow thinks her own bird the fairest (Am.). Each old crow thinks her young are the blackest (Am.). Every mother's duck is a swan (Am.). Every mother thinks her own gosling a swan (Br.). The owl thinks all her young ones beauties (Am.). The owl thinks her own young fairest (Br.). There's only one pretty child in the world and every mother has it (Br.)