Basically, she thinks that living/marrying the guy has zero ramification on what I should be paying her for support. Morally, I think that's not right; obviously, what that courts think is the trump on us both.
Sorry, but your ex-wife is correct. Even if she were to quit her job, the state would input her income at what she is cabable of earning to calculate child support.
And "morally"...you think it's ok to be FORCED to support children that aren't yours? If so, then you won't have a problem with paying ME CS for MY kids...no difference.