Light Brown area on stomach

My 6 year old daughter has now started asking questions about an area, light brown in colour on her stomach to the left of her navel.(3 1/2 inches by 1 1/2 inches). She was born with it and has grown with her. I have just assumed it was a birth mark, but don't know the correct name for it. Can anyone help. What is the best product to use to cover it up.
Any help gratefully appreciated.

[nickbar]

It sounds like a cafe-au-lait spot. Is it flat?

Here is a link to more information about cafe-au-lait spots.
http://www.rainbowpediatrics.net/cgi...unction=logout

http://my.webmd.com/hw/health_guide_...p?pagenumber=2

For cover up information. Look under the PWS discussions. There are makeups that people recommend for covering PWS, might work very well for her spot, if you feel it needs to be covered?

Corinne