If the biological parents put the needs of the child first and not their own selfish ones, they would allow the child to be adopted by the foster parents. Any way you cut it, that's what's best for the CHILD. The bottom line is that in the end for the biological parents it was about winning. Sad.
I don't believe it is selfish to want to raise your child that was wrongfully taken away from you and not returned.
How did you determine what is BEST for the child. Income, parents education, etc.
You don't think the daughter would later have abandonment issues and question "Why didn't my parents love me enough to fight for me."
I'm wondering if, in fact, the bioparents are doing this themselves or under some pressure from the Chinese government? China, for all its efforts to control its population through whatever means, nonetheless doesn't like losing its people to the West.