Is it permissible for a husband to order his wife to cover her face and not wear makeup in front of her sister's adult sons?

The maternal aunt is permanently forbidden in marriage to her sister's sons. It is permissible for them to look at her, be alone with her, and kiss her (on the forehead or head) if there is no fear of temptation. She may also display her adornment in front of them. Do not prevent your wife from this unless you find suspicion or fear of temptation. And both spouses must treat each other with kindness.