Okay, this one hits close to home for me because I've been on this exact hunt before, and let me tell you, it's less about finding a specific 'where' and more about spotting the tags and vibes that promise the emotional payoff. The popular romance platforms have plenty of bossy-female-lead stuff, but a lot of it is just surface-level power play—hot but forgettable. I found my best reads by looking past the obvious 'Femdom' tag and digging for 'gentle femdom' or 'service top' combined with 'emotional hurt/comfort' or 'married couple'. That combo often hints at a dynamic where the dominance is an expression of deep care and established intimacy, not just performative control.
A specific spot I'd point you to is the indie author section on platforms like Amazon. A lot of the big-name stuff in that niche can feel a bit formulaic, but I stumbled on 'The Arrangement' by someone named Rebekah Weatherspoon? It's technically a series, but the first book, 'Haven', centers on a married couple renegotiating their dynamic after a trauma. The wife's dominance is so deeply tied to protecting and healing her husband; it's fierce and tender at the same time. You won't find that emotional layering in most of the top 100 lists.
Don't overlook fanfiction either, seriously. Some of the most nuanced explorations of power and care in established relationships happen there. Filter for a fandom you like, then search for tags like 'established relationship', 'domestic', and 'power dynamics'. The writing can be hit or miss, but the hits are spectacular because the authors are writing purely for the character exploration, not market trends. That's where I've read some stories where the 'dom wife' element is so woven into the fabric of their daily life—choosing his clothes, guiding conversations at a party—that it feels less like a scene and more like a language of love they've built together over years.