Is it permissible for an iddah-observing mother to stay overnight with her daughter who is about to give birth in order to serve her, or must she stay overnight in her own home?

A woman observing the 'iddah (waiting period) after her husband's death must remain in the marital home and spend the nights there throughout her 'iddah period. She is permitted to go out during the day for a need or necessity, but she is not allowed to spend the night outside the home unless it is due to necessity. She is not allowed to go out for purposes other than necessity or need, such as recreation or 'Umrah. Similarly, she is not permitted to spend part of her night outside her home. If it is imperative for the mother to stay with her daughter because the daughter needs someone to serve her, then the daughter must move to her mother's house. The social custom that permits the mother to stay with her daughter to assist her after childbirth is not a valid justification for violating the Sharia's command for the woman observing 'iddah to remain in her home.