The James Randi Educational Foundation investigates paranornal claims, like the existence of Indigo Children, and offers a one million dollar prize if such claims can be shown to be real. I think the Indigo Children claim is formally testable and money won could be invested in furthering research into the Indigo phenomenon -- a very good thing!
I would think that the only reason to not apply would be fear that the Indigo phenomenon is not real, or that one's own child is not an Indigo. So if one is completely confident that one's child is Indigo, then one should rush to apply. To hesitate is to admit doubt.
One can learn about the prize by visiting this web site:
http://www.randi.org/
...then click on the $1 million Paranormal Challenge button at the top.
To apply, read the rules, send in the application with notarized applications and the other necessities, and the application will be able to reach the next step.
Even though application processing is temporarily on hold, it seems like a good idea to have the application on the challenge desk when it resumes.
Good luck!