China run - David Ball

The days leading up to the adoption had been trying. Allison Turk's husband got sick and couldn't make the trip, so they decided that Tyler, Allison's nine year old stepson, would accompany her to China. They hoped the time spent together would improve their strained relationship, but it wasn't working out that way.
For Allison, the waiting was the hardest part - days of doing nothing while Chinese officials processed reams of documents. Then, six days before she was to return home, she finally held in her arms the beautiful little girl she had only known from pictures. But the joyous feeling didn't last long. Within days, she was summoned to an emergency meeting of adoptive parents. A mistake had been made - 'a clerical error' - the parents would have to return their babies, and they would be given new babies in a few days. Distraught over the prospect of surrendering the child she had come to love so intensely, Allison joins another couple and a single mother who have decided to defy the order and make a run for the American consulate in Shanghai.
What ensues is a tense, dramatic and totally believable race, in which Allison struggles with her infant girl and recalcitrant stepson, until her luck runs out.