Diamonds and Toads

Diamonds and Toads, also known as Toads and Diamonds, is a French fairy tale by Charles Perrault, originally titled Les Fées ("The Fairies"). It was later included by Andrew Lang in The Blue Fairy Book and illustrated by Laura Valentine in Aunt Louisa's Nursery Favourite.
In Perrault's version, as with tales like Mother Hulda, the kind girl is a stepdaughter. However, some retellings altered this to reduce its resemblance to Cinderella.
The story follows a bad-tempered widow with two daughters. The elder daughter, proud and disagreeable, takes after her mother in both appearance and character, making her the favorite. The younger daughter, kind, gentle, and beautiful, resembles her deceased father and is treated cruelly by both her mother and sister.
One day, while fetching water from a well, the younger girl meets an old woman who asks for a drink. She kindly obliges, only to discover that the woman is a fairy in disguise, testing the hearts of mortals. Impressed by the girl's kindness, the fairy blesses her so that every time she speaks, jewels or flowers fall from her mouth.
When the girl returns home and explains the encounter, her mother is thrilled by the magical gift and insists that her favored elder daughter must receive the same blessing. Though reluctant, the elder daughter is forced to go to the well. There, she meets the fairy, who now appears as a regal lady and again asks for water. The elder girl rudely refuses and mocks her. As punishment, the fairy curses her so that toads or snakes will fall from her mouth whenever she speaks.
When the elder daughter returns home and speaks, toads and vipers fall from her lips, horrifying her mother. Enraged, the widow drives the younger girl out of the house. Alone in the woods, the kind girl meets a prince who falls in love with her and marries her. In the end, the widow, disgusted and overwhelmed by her older daughter’s curse, casts her out as well. The elder daughter eventually dies alone and forgotten in the wilderness.