In 2014, women made 83 cents for every dollar earned by a man. Single women without children earn 94 cents for each dollar earned by a man, whereas married mothers made only 77 cents.
Naomi is in dire straits because, as a widow with no offspring, there's no way for her to be provided for—and especially not in a foreign land that has no rules for providing for widows like Israel does.
She had only this one relationship left in all the world, and the poor, unfortunate, widowed and childless woman had cherished it with all the tenderness hoarded in her heart.