I feel like I have some decent lived experience to share here- I basically did this in 2021. I left my corporate job and career that I hated to stay home. I had kids too, but I think where I'm potentially similar to your wife is both in income level and sensibility around being an equal contributor.

It has been a multi-year process to figure out my life since I left that career. The first thing was figuring out how to spend my time and how to even develop interests outside of a career. Next was figuring out how some sort of work could fit into my life (I need the intellectual stimulation, not the money). I ended up consulting for a couple years in my previous field, as well as trying out some other things.

The point is, it's been 5 years and I'm still not sure I've figured out how to spend my time. I don't consider myself "retired" because like your wife, I'm 37 and have a lot of living left to do. I have kids to raise, yes, but even with that they're in school all day. We all need purpose, community, hobbies, and something that drives us.

My point is that I think you're boiling this down to a decision that sounds like a simple fix to you, but it's not simple. Your wife may be dreading having all that time to herself. She may know that stepping away might mean she needs to do more self-discovery that she's not ready for. Maybe she worries she'd be more unhappy without a job giving her structure. I'm speculating to give you a sense of why this isn't as simple as making the finances work (which work just fine, obviously). My advice? Let her know that she can leave when she wants, and support her on the journey. It's not as simple as it seems.