I don't think she is a bad writer, I think this paragraph is hilarious:
Because the way things were going it?s hard to imagine how such intensively reared children (so safely kept and so healthily fed that they?ll probably never die) are ever going to be able to fend for themselves. The pair of them, like so many of these fashionably over-mothered children, looked set to be a charmless burden on generations of taxpayers from the moment they leave their nest until the moment the world is submerged by melted ice caps.
Of course it is a bit of a silly article but she clearly was just completely irritated by a woman on a train, and had to make up a column about something.
Actually that mum was probably a goldman sachs analyst who was overcompensating, or something.