A.S.
My husband and I work together. We try to alternate when the kids are sick and need to be home/taken to the Dr. I don't take more than 40hrs of sick time in the entire YEAR. But most working moms that I personally know (no offense to those that don't or do), don't make upwards of $70K/yr and the larger portion of the family income. If I was the one making less, I'd probably be more inclined to stay home in any instance needed.
But let me tell you... The company I work for... Rarely lays off (crosses fingers - hasn't laid off since 78) and I've only seen a handful of people get fired. It took a LOT for that handful to get fired. So, my situation is different than most (I think). We have it pretty good and easy here.
As far as 'keep mommy sane days', probably once a month (but I have 3wks paid vacation). I usually use the first wk as a 'day here/day there' and take a weeks vacation with family and a weeks vacation for ME.