Your suspicions aren't completely unfounded, Bucky, however you are approaching this with the wrong attitude. You seem to have the notion that being a stay-at-home mother is a soulless, unfufilling role in life. It isn't. Women do make this choice over having a career every day. If it's what they want, then good for them. I'm sure your sisters are intelligent enough to know what they want and I'm sure that if they change their mind, they'll have the resources they need to do so.
The point of this that really ticks me off is that you think you have the right to make that decision for them. It's not your place to judge them or their ambitions. If you do that, you're no better than the misogynists that say that they shouldn't be allowed to have a career. It isn't your place to decide what is right and wrong for them, and to act like it is defeats the entire point of the feminist movement. And the Jee-man didn't do anything this time, so leave him out of it.
However, to be fair, your thinking is in the right area. Career women in American society are still looked down upon and often face undue burdens. The idea of women as caregivers and men as breadwinners is still extremely prevalent, and people are crushed by it every day. But even that notion is changing, as more women enter the workforce and head their own companies, and more men decide that caring for their children takes precedence over their career. There's more antipathy out there than I care to address in this one post, but that things are changing is enough to give me a sliver of hope.
Bucky, I'm happy that you would embrace a more progressive lifestyle and love life. But do not push that on others at the expense of their individual happiness.