What led to grusha married to Jussup

Lavrenti (Grusha's brother) informs Grusha that must marry a dying man from the other side of the mountain. That way she leaves the house and Michael is made a "legitimate" child since he will then have a father.

She protests, but Lavrenti explains that "you don't need a man in bed - you need a man on paper." Since the man is dying, Grusha finally agrees to marry him so that she can become a widow.