What is the ruling on a woman leaving her house during her husband's 'iddah (waiting period after death), and her receiving her husband's brother in her house during the 'iddah in the presence of her adult sons?

It is permissible for a woman to leave her house during her 'iddah (waiting period) after her husband's death for a legitimate purpose. It is also permissible for her to receive her husband's brother in her home, provided there is no unlawful seclusion (khalwa), no soft speech, and no display of adornment in front of him. Furthermore, communication with him should be limited to what is necessary, while maintaining proper decorum and dignity.