Donna's sister from back home

Donna doesn't really talk about her family and when she does it is mostly about her dad. She doesn't talk about the fact she has a sister to anyone but Harvey and that was only once, the reason for this is the fact that she doesn't want her sister in this world. This the story of how Donna's younger sister comes to New York. The reason unknown to Donna. Read it meet Daisy Paulson.