Something to think about when you’re watching the new “Keeping Up with the Kardashians” this weekend: For every piece of this family’s massive empire, matriarch Kris Jenner takes a 10% cut. And when business and family mix, you can’t help but wonder how the lines get blurred. Does being your child’s manager get in the way of being a good mom? This week, Buzzfeed’s Zan Romanoff walks us through the history and stigma of the “Momager,” and we hear from a real-life stage mom about her day-to-day.