Okonjo iwealas son engaged to chinua achebes granddaughter
I think there may be some confusion here!
Okonjo-Iweala is a Nigerian economist and former Minister of Finance, while Chinua Achebe was a renowned Nigerian novelist and poet. While both are prominent figures in Nigerian society, I'm not aware of any connection between them that would lead to a familial relationship between Okonjo-Iweala's son and Chinua Achebe's granddaughter.
It's possible that you may have come across a fictional or satirical article or social media post that fabricated this information. I'd be happy to help you fact-check or verify any information you may have come across!