Assalaamu alaikum warahmathullahi wabarakatuh!
I enjoyed reading the book. It was worthwhile. However, there are a few things I wanted to point out in case you want to edit this book in the future.
Both the MCs spending time in a closed room is not very encouraging. Although the slave was just outside, it is still not permissible. It is a sin even if they had come together to worship their Creator.
Mayera's mother giving her away is not acceptable either. The nikkah is not valid, and a woman who still proceeds on with this relationship is considered an adulteress.
About Sa'eed wanting to take up administrative duties, I hope you are aware what Prophet Muhammad SAW said when Khusro's daughter was to succeed him.
How could have Zain met Meher when she had not left the house in the two years of her marital imprisonment, and had entered her iddah soon after Mir Jafar was hanged?
Maybe you could tweak all these things a bit?