That is very cute! The purple fabric looks to be a glazed cotton which is found quite often on vintage and antique children's Halloween costumes, as it was a very inexpensive fabric mostly used for lining women's garments, Victorian hat linings, etc. The yellow looks like a thin cotton or rayon lining fabric also.
These old costumes can be hard to date, as the fabric could be much older than the finished costume. The yarn balls could have been added later as the colors do not match well. As typical of these, it was obviously sewn up very quickly using basic and simple stitches. My guess is it is pre 1950s, but I really cannot tell much, that's just a guess.
