What I'm about to say might make no sense at all, but I seem to remember (or at least think I do, it might be a false memory arising from thinking too much about it) slowly gaining consciousness in early childhood.
I have a birthmark on the back of my hand and some of my earliest memories are triggered by noticing it and realizing I’m a separate being from other people and can influence my actions, stop being a mere observer of my body running on “autopilot”.
I have only passing knowledge of lucid dreaming, but from what I’ve read I’d say becoming a lucid dreamer is not at all dissimilar to developing consciousness in childhood. So maybe that’s a potential avenue for consciousness research.