If you research so much regarding the fire, the buildings, the chemical und physical reactions behind it... please do the same courtesy towards the actual people, the actual human beings who lived during and before?
If you want to write fantasy fiction, please do so and do not warp actual timelines of real human lives of people who actually lived.
For example: Lucy Walters died in 1658.
The book has her as an important plot point, alive, in 1666.
The plot and the main fictional characters: superficial, sensationalist, annoyingly obtuse.
It's ok fast food for kindleunlimited but i wouldn't pay money for it otherwise.