Ok I will explain the three stories on in my opinion on what could they directly mean and be interpreted. Because I know some people get confused on who is who and including the RUIN and HW2 stories so I shall define them for you. You can disagree with me if you want but don't go to far.
So the first story is about a woman who was sealed in a small room that had a furnace and five keys. She was told that each of the five keys would unlock one of five doors outside her room. Inside each room was a child that she could take with her as she fled the building. But she was only allowed to leave her own room with one key, not all five. She wanted to save these kids so she melted all five keys to make one key as she thought it would open one door but it didn't work and the five kids died with her. So in my opinion the woman is refereed as the Puppet who is possessed by Charlotte Emily and is theorized to have given the MCs (who are the five kids in this story) their animatronic forms. The woman is mentioned to have melted the 5 keys into 1 and failed to unlock the doors, which can suggest on how Charlie and the MCs fell victim to their killer, William Afton.
The 2nd story is about the a kind man that adopted 5 kids and a burglar that killed the 5 kids and leading the kind man to stich their 5 bodies into one as he couldn't afford 5 coffins so he stitched them in one body so he can burry them in one coffin. In my opinion the kind man and burglar are one and the same as I do think the kind man is persona of William's clever and manipulative side and the burglar is his sadistic and murderous side. The 5 kids are the MCs and I do think the story is hinting at Molten Freddy as he is theorized to posses all five kids and that Molten Freddy was a huge amount of animatronics all bunched into one and these animatronics were made by William Afton and can allude to the 5 bodies stitched into one and into one coffin to get buried.
The 3rd story is about a little boy who found 5 kittens and who owned a red snake that ate the kittens in 5 nights and in turn the boy killed it. The little boy could be Michael Afton who went through security nights, the snake who is theorized to be William Afton killed the 5 kittens who are theorized to be the MCIs which leads Michael in the end to plot to kill his father in FNAF 6. You can think the boy is Crying Child but he didn't kill anyone, especially William.
In RUIN, Candy Cadet's story about the mother and her son is meant to be foreshadowing towards The Mimic, due to the monster in the story learning to mimic the mother's lullaby to trick the boy, similarly to the Mimic mimicking Gregory to trick Cassie. Though some theorize that the story foreshadows two meanings. One with the mother being Vanessa and the boy being Gregory who both found the Mimic and trapped it. Number two being the mother's role been given to Gregory and the son's role to Cassie and her being lured in by the Mimic.
In HW2 It is unknown what Candy Cadet's stories could mean or represent. One story is about a family dying because they didn't purchase a four for one deal at an unnamed pizzeria (possibly a Fazbear location) and is fairly decided is irrelevant to the lore.
Some theorized it's about the Afton Family and the deal being them possibly not getting to become a loving family and later causing to their ugly demise. The other story is about a young woman that was tricked by a young boy and eaten by a witch. This could represent Vanessa or be foreshadowing Cassie's fate.