Enola Holmes - not quite done yet, but I have a few thoughts already.
As the world progresses during the sufferage movement, Enola is the characterised expression of liberated womanhood. A devotion to subjectivism and individuality rather than the objectification of women as described and criticised by Mary Wollstonecraft. The force of restraint and extinction of passion within its infancy is a tool to create conformity in subjugation. Somewhat like Jane Eyre, there is an element of conforming in order to survive, but nobody can acheive greatness by not standing out. While in Jane Eyre, the wildness was stifled, down to a glimmering ember, the "modern" woman is reclaiming it from the prison of the post-Victorian patriarchy in order to self-actualise and integrate the female psyche into society.
It sure remains a relevant topic but it's far from the only theme discussed, as there is a more generalised lesson for the watcher involved as well: changes in a society come about more violently and swiftly the more the regime tries to keep things from changing.
*She has something akin to Sally Lockhart imo.
The portrayals of the bothers Holmes wasn't flawless, but inspiration leaves a lot of room for interpretation.