A Pocahontas costume would be easy peasy to make - toss me a couple yards of soft brown fabric and I could make one, stat!
Costume stores have sales this time of year (online) and a women's costume might do. You could take it in here and there - if the bust darts were too much, for example.
When I have a child that complains their costume is 'itchy', I have them put it on and identify the areas. Then I take long strips of white felt (about an inch wide) and tack it (sew) over the itchy areas. Works a dream!