This is my opinion on the subject: There are not 'Indigo childrens'.
The Indigo girls is just a useless label created by some people.
Children are children. They are all equal. I believ all the childrens comes from the same Light/God. We are one.
So, in my opinion, 'Indigo children' doesn't extist at all. 'Indigo' is just another attempt -made by some people- to create useless divisions on this world.
I'm wondering why people from all over the world tries to create division and separation. We are one, we are the same, we have the same right to love and be loved. Specially childrens. Nothing else really matters.