The Question and Answer section for Oliver Twist is a great resource to ask questions, find answers, and discuss the novel.
The authorities at the workhouse take care of Oliver. They don't actually take care of him: they send him to a baby farm run by Mrs. Mann.
The word festive is meant to be sarcastic. Porridge is not a festive meal..... it's gruel mean to fill the stomach, nothing more. Unfortunately, the boys were not even given enough to fill their bellys.
Nancy eventually betrays Fagin and Sikes to save Oliver, but she will not leave them, and pays her life for this decision. I don't think Fagin was her friend.