Not only do people's decisions with marijuana and their children make the news, but I've also had my own experience with this. And neither the weed nor the child was mine.
In the summer, my friends and I like to go rafting down the Youghiogheny River (nicknamed The Mighty Yough and deserving of its own post - so many tires), usually from Connellsville to Dawson, the stretch that just happens to have the most people who are usually very interesting, to say the least.
Of course the river is really crowded on hot days, and as a result the early part of the trip is spent pretty close to other rafters - close enough to see someone else's alcohol supply and trade them some Smirnoff for a beer, for example. Also close enough to smell their weed.
Weed in Fayette County seems to be pretty common, so someone smoking on the river isn't really surprising. Plus it's usually a pretty shallow, calm river. But then we noticed that the raft with the weed also had a baby.
The weed in the Elmo backpack and weed hidden in a dirty diaper hadn't happened yet, so we were shocked. Our whispered reactions were something like, "Oh man, why would you smoke weed around a baby?" Then we realized that taking a baby on a river, no matter how shallow, was also a pretty terrible idea.