Two biological sisters grew up separated, not even knowing each other existed. Both adopted, the girls ended up attending the same college. Their birth mother placed the girls for adoption years ago, just a year apart from each other, because she wanted them to have their best chances at life.
Coincidentally, both girls signed up for the same writing class at Columbia University. During class conversation, as they got to know each other a little better, the sisters recognized their commonality. Conversation led to adoption which led the two to discover that they are sisters! One of the sisters had found their mother a few years earlier, and so the two contacted their birth mother to share the good news. The girls and mother will be reunited at the graduation ceremony.