Duplicates and next hunt

I've discovered that I have non related or duplicate people in my tree.  I think that's from not really knowing what I was doing in the beginning.  I merged every hint I received from Ancestry.  I've now realized that some of those may have not been my relative or the information was wrong.  Now, I'm spending my extra time fixing my links and deleting people.  I'm hoping to start locating birth records and ordering copies.  I have my hanging files and folders organized but I still need to get my computer files organized.  I'm going to use the system that is used by Lisa Louise Cooke, the creator/host of Genealogy Gems Podcasts.  My family seems to be out there and very accessable I haven't had any brick walls yet.  My aunt told me that my great great grandmother was Native American but I haven't found that.  That's my next adventure is to find out more information on Virginia Ann Marshall b Dec 29, 1849 in Indiana and died Feb 21, 1922 in Effingham, Illinois.  Is she Native American Indian?