* You teach the child dishonesty (taking credit for someone elses work can terminate your academic career).
* In this particular case, the child becomes the face of a marketing campaign (that's her actual contribution: selling a product).
* Stories like this one put pressure on other children because their parents buy it hook line and sinker and want the same for their children.
* is able to infuse carbon nanotubes with chlorine and build a disposable sensor from this.
* understands marketing enough to promote her product via the app stores (there really is no other reason for using a smartphone instead of three colored LEDs to display results).
Is anyone really buying this?
Here's a more likely story:
* Parents see scientific curiosity in her daughter, as well as the will to help people.
* Parents see a fear of lead in water and therefore a market for testkits
* Parents see that testkits already on the market suffer
from being unreliable in untrained hands/too difficult to use.
* Parents have the idea for a better, "digital testkit", but that turns out to be way more expensive than anything that is already on the market.
* Parents then spoonfeed the idea to her daughter. They do the work, she gets the credit (and probably thinks that she did most of the work).
* The media picks the story up because "awwwww ... smart kid", resulting in free marketing for what would otherwise be a totally overengineered/overpriced product.