Day of the Triffids meets Gretchen Felker-Martin's Cuckoo.

This is just a story. It can't hurt you anymore.
Since she was three years old, Anastasia Miller has been telling anyone who would listen that she's an alien disguised as a human being, and that the armada that left her on Earth is coming for her. Since she was three years old, no one has believed her.
Now, with an alien signal from the stars being broadcast around the world, humanity is finally starting to realize that it's already been warned, and it may be too late. The invasion is coming, Stasia's biological family is on the way to bring her home, and very few family reunions are willing to cross the gulf of space for just one misplaced child.
What happens when you know what's coming, and just refuse to listen?
A Macmillan Audio production from Tor Nightfire.