How can you tell someones indian?

I have a little bit of indian in me and just a few days ago one of my moms old friends saw me for the first time since I was a baby..and the first thing she said to me was that she could tell I was indian..but I have light brown hair and blue eyes..so I really dont know how she could tell?..anybody know?
Thanks!

The color of your skin could be a sign some people who are light tan and they have some Indian in them.

As far as I know, there is no way to tell other than doing a family tree and seeing who your ancestors are.