Today is the feast day of St. Gianna Beretta Molla, one of my favorite saints. She lived in very recent times, dying in 1962, was a wife, mother and doctor - a true 'working mom' by today's definition. She is a fantastic example of devotion to God and the family, eventually giving her life so that her fourth child could live.
Check out the website to learn more. I especially like this page that gives a timeline of her life and subsequent canonization. Be sure to click on the links in the left column for more details on things that interest you. (More specifically, Mom, click on the "Medical Circumstances of Death".)