No spoilers beyond the back-cover.
The idea of selling children to rich families is hardly unique. Long-lost siblings being re-united is a great theme. The family drama that leads to the first step of this discovery is, for me, overdone: it could have been simpler and still a great story. But that’s just me, I can’t speak for everyone.
The contrast between the various paired homes is amazingly drawn.
The story has various forms of abuse, both detailed and delicately hinted at.
Happy ending, though.