The majority of people don't know what they want to be in life. External factors will force you to make decisions which deviate from any aims/paths you wish to follow. She's already inspired a great number of people to follow maths by contributing to this website.
The main thing that you should take away from the article is:
"Clearly, you can become a foreign correspondent for a major and respected publication without having done maths at university, but Helen's career is a great example of where mathematical training (and it doesn't have to be a PhD) can take you.
"It's maths that landed me the job at The Economist in the first place, because it gave me that little edge over other applicants." Writing about politics and economics, it's obviously essential to be numerate and in particular to understand statistics, but mathematics also gives you other, less tangible and highly transferable skills: being able to understand and convey difficult ideas, follow chains of reasoning and spot regularities in a confounding mass of information. In this wider sense, maths truly is a multi-purpose subject."