Is it permissible for a woman observing 'iddah to go to her brother's house, which is adjacent to her parents' house, to receive guests and then return to her parents' house, in order to avoid inconveniencing her mother?

A woman observing the 'iddah (waiting period) after her husband's death is permitted to leave her home during the day for a necessity, but she should not go out at night except in cases of dire necessity. This is based on what was narrated from the Prophet, peace and blessings be upon him, in the hadith of Jabir, and his saying to Mujahid. You are permitted to go to your brother's house during the day to receive visitors if their visit would cause distress to your mother.