It sounds obvious, but you'd be surprised. 

Leslie Bennetts speaks below about what happens to women’s livelihoods when they drop out of the workforce.  She focuses on stay-at-home mothers.  I’m less interested in the kid-aspect, but find the video riveting anyway, because women AND men taking time off for any reason (elderly parents, illness, etc.) would face the same issues she’s researched.  The video is about 30 minutes of lecture and 30 minutes of Q&A.

For the sake of your cash, be informed.