Movie called baby- baby found on front porch?

I remember around 8 years ago watching a movie and if I remember correctly it was simply called "Baby". I must have the wrong name but it was baby something. It was about a little girl baby that was left on the front step of a family. They lived on an island and they take the baby in. It mainly revolves around the mother and her teenage daughter who take in the baby. The birth mother ends up sending letters and stuff and the teenage daughter hides them. Also it shows scenes at her school with her teacher who inspires her. At the end of the movie, the mom comes back and takes the baby back on the ferry with her. I wish I could find this movie, if anyone knows what it is called please let me know!