What is the ruling on a girl performing istikhara concerning marriage to a committed young man who has not proposed to her, and what is the ruling on a female friend asking her husband to speak with the young man to propose to her on behalf of the girl, based on her desire?

There is no harm in a woman offering herself in marriage to someone she perceives to be good and righteous, as was the practice of the predecessors (Salaf). The Istikhara prayer should be performed after the other party has agreed. It is permissible to supplicate to Allah to grant her that person and to make him a source of good for her.