Is it permissible for a mother observing 'iddah to go out with her daughter to buy wedding supplies due to the lack of another alternative?

An Umm al-Mu'taddah (a woman observing the 'iddah period) is permitted to go out during the day to purchase necessities if there is a need for it, provided she does not spend the night outside her home and does not go out at night except for necessity. Some scholars have restricted her going out to cases of need, while others have not.