If shes single, her combined effective federal and Missouri income tax is around 40%, so she took home roughly 600k. If she’s married, then her total effective tax is 25%, so she took home 750k.
For the 600k investment at a conservative 4%, which right now you can get in some savings accounts, her interest alone would be 24k/yr. For the 750k, it would be 30k/yr.
With a more realistic return of 7-8% in today’s high interest rate markets, both of those sums would net more than her old salary of 42k/yr.