Charging Women Less Than Men: Is This Legal?

And how will their respective supervisors reflect on their time off come promotion time?

I aggressively keep my personal life out of the work place, but I still see myself being gently but persistently directed into the mommy-track in a way my husband isn’t. It’s obnoxious.

Actually, what their supervisors think doesn’t really matter at all.Both are government jobs at large agencies , where you get promoted based on test scores and interviews by management in the area where the opening exists- and they don’t have access to records of when or why you took leave. They have access to disciplinary records and evaluations but those only cover whether you follow the attendance policy. Sure, some dinosaur of a supervisor could think " Jim doesn’t deserve to be promoted- he’s always staying home to take care of his sick kids" - but he would never say it to the people making the decision. Because if Jim gets promoted, he’ll be someone else’s problem, not the dinosaur’s. I realize that most work places aren’t like this- but these ones are.
And still the men don’t take the child-care leave they are entitled to and they don’t stay home with the sick kids. I won’t speculate about why - but in these cases it isn’t that they will hurt their chances of getting promoted or because their wives earn less or have more time off.

You must be familiar with a very different type of government job than the ones I am. In my experience, yes, a person can coast along on scheduled pay raises. But if a person hopes to take leadership positions or move to prestigious departments, they need every bit of political clout they can get-- and impressing individuals matters very much.

YMMV

Yep, it’s different all right.
But I didn’t say impressing people doesn’t matter - I said the opinion of the supervisor who would know when and why you took leave wouldn’t matter. If I’m interviewing someone , my impression of them certainly will matter - but 99.9% of the time I won’t know that they took a day off two weeks ago because their kid was sick or that they took a six month child-care leave two years ago or that they ask for the whole month of July off every year because the spouse is a teacher. (I will only know that if one of my indirect reports gets a high enough score on the test that I am allowed to interview them , I’ve supervised them long enough to know when and why they took leave and it’s a long enough leave for me to notice, not a day here and there because of a sick kid. Hasn’t happened once in eight years- the one time interviewed someone in my own area, I had only been assigned there for two or three months myself.)