Between then and Halloween, two family members changed their costumes.
Instead of a blond little Chinese fellow, we had the amazing:

This is what Mathison originally wanted to wear for the party; this costume is on loan and we hadn't gotten it yet.
As for the second switch, Krissia decided on:

When the movie first came out, several people commented that the avatar princess reminded them of Krissia. She decided to play up this resemblance; I think she looked great! Krissia was in charge of passing out candy at our house between 6 and 7 p.m., and several trick or treaters who came to our door during that time asked to get their picture taken with her.
Here's a closeup which offers a better look at the detail:

Krissia used blue craft paint on her skin, and although she showered thoroughly last night, she still looked a little aqua this morning at church :) The preparation that took the longest, though, was her hair. It takes a while to section and plait that many braids! It paid off; Krissia won first place last night for "Best Costume" at the Dixie College Halloween Howl. Everyone called her "Avatar Girl".
If there's ever a sequel to the movie, maybe she should audition for a part :)