Loving-kindness (Hebrew: Hesed) and redemption are a theme of the book of Ruth.
Ruth showed loving kindness to her mother-in-law Naomi by not abandoning her, tied together in a relationship of caring for Naomi until death. This act of loyalty certainly heavily decreased Ruth's possibility of finding another husband in the future and may have resulted in Ruth remaining widowed until death herself.
Ruth 1: 16 But Ruth said, “Do not urge me to leave you or to return from following you. For where you go I will go, and where you lodge I will lodge. Your people shall be my people, and your God my God. 17 Where you die I will die, and there will I be buried. May the Lord do so to me and more also if anything but death parts me from you.” 18 And when Naomi saw that she was determined to go with her, she said no more.
Boaz shows loving-kindness redeems the property of Naomi AND Naomi and Ruth (something that was not required). Boaz marries Ruth. They have the child Obed ( meaning "servant" or "worshiper" ) so that the lineage of Naomi's dead son, Mahlon, was technically redeemed, too, according to Levitical Law.
Ruth and Boaz Marry
Ruth 4:13 So Boaz took Ruth, and she became his wife. And he went in to her, and the Lord gave her conception, and she bore a son. 14 Then the women said to Naomi, “Blessed be the Lord, who has not left you this day without a redeemer, and may his name be renowned in Israel! 15 He shall be to you a restorer of life and a nourisher of your old age, for your daughter-in-law who loves you, who is more to you than seven sons, has given birth to him.” 16 Then Naomi took the child and laid him on her lap and became his nurse. 17 And the women of the neighborhood gave him a name, saying, “A son has been born to Naomi.” They named him Obed. He was the father of Jesse, the father of David.
The Genealogy of David
18 Now these are the generations of Perez: Perez fathered Hezron, 19 Hezron fathered Ram, Ram fathered Amminadab, 20 Amminadab fathered Nahshon, Nahshon fathered Salmon, 21 Salmon fathered Boaz, Boaz fathered Obed, 22 Obed fathered Jesse, and Jesse fathered David.
This seemingly isolated tale results in continuation along towards the messianic line of David and ultimately Joseph, who betrothed Mary, the mother of Jesus!
The courage and loving-kindness of Ruth may not seem like Supergirl comic book heroics, but it involves a heroine of strong character who demonstrates godliness, boldness mixed with humility, loyalty and love.