who puts a blanket around scouts shoulders when there around the campfire

boo radley

First of all, the question should read, "...when they are around Miss Maudie's house while it burned down..." There is no campfire and "there" is used incorrectly. It is "they're."

Boo Radley puts the brown blanket on Scout's shoulders. We know this because he is the only person in the neighborhood who is not "at" the fire.