It looks like it's final. I got an email from my publisher today and he tells me that the marketing team has decided the title is to be....
The Other Daughter
My title, Yesterday's Child, was being used by a number of books and they wanted something that was representative of the tension inherant in the story line as well as giving a hint to the plot.
The cover is being worked on right now and I was told I'd get to take a peek at it, as soon as it's a little further along. I won't be able to share it immediately, but as soon as I have permission, I'll post a pic of it here. It's also looking like the book might be released in October, if all goes well. Exciting stuff to be in time for Christmas giving!