Is it permissible for women to confide in one another about the worries and hardships of this worldly life, or is that considered a complaint to other than Allah and contrary to gratitude and patience?

If the outpouring of feelings is free from forbidden things such as backbiting, lying, speaking about marital relations, and expressing discontent with destiny, and is merely a pouring out of worries or a problem to seek a solution, then there is no harm in that. Mere complaining is not blameworthy unless it is accompanied by discontent with what Allah has decreed. The servant has been entrusted not to fall into what he has a way to abandon during a calamity, such as excessive groaning and exaggerated grief. As for mere complaining, it is not blameworthy until discontent with the divine decree occurs.