Fair Way To Do Prenup Spousal Support

Me 27 and my Fiancee 27 are in a pretty uncommon situation. Right now I make 500k per year, but it’s not maintainable. I have to work long hours under high stress and it is affecting my mental health. If i was working a normal job i think I would make closer to 100-150k. Ideally depending on our savings I would like to take a job that I’m more passionate about such as teaching and making closer to 70k. I want to make sure that in the event of a divorce, and me going to a lower paying job a judge doesn’t say that my imputed income should be 500k. Our combined spend is 110k (no kids). Because I have been doing this for a few years i have close to 1 million in savings. My fiancé is worried that if theres no underemployment protections then I have the financial ability to not work and just live off interest in savings, and paying no alimony. She wants to make sure she is protected in the event that we have kids, shes stay at home mom, and after being out of the workforce has a tough time re-entering. What are some fair ways i can protect myself from being held to a 500k imputed salary. Is this a real concern or will a judge realize that i only made 500k by working crazy hours.