father in law, older brother in law, jealousy
嫜 centers on a woman's relationship to her husband's male relatives, specifically father-in-law and older brother-in-law. The jealousy meaning is a separate, less common sense that may arise from the emotional dynamics of those relationships.
嫜 combines 女 (woman) with 章, which likely contributes the sound. The exact historical development is uncertain, but the character is associated with female in-law relationships.
A woman 女 standing beside a display or badge 章, representing the formal roles of her husband's male relatives: father-in-law and older brother-in-law.
For ショウ, imagine a woman showing her father-in-law a new badge: show -> ショウ, and the woman 女 presents the badge 章 to her in-law.