How can one deal with relatives who exhibit envy and belittlement, and claim virtue while their actions contradict the principles of religion?

The hijab is an absolute obligation. It is not permissible to accuse relatives of hypocrisy or envy. Enjoining good and forbidding evil is obligatory, with its specific conditions, and it is not a prerequisite for it that one be free from sin. The person being advised should accept the advice and not make excuses about the shortcomings of the one offering it. One should treat relatives with kindness, accept their advice, offer sincere advice to them, think well of them, and interpret their actions and words in the best possible light. Complimenting with kind words and good deeds fosters affection and removes animosity.