Brioche Knitting

My balaclava is about halfway complete! I know how to do brioche knitting and it isn't hard! I did make an error in one of my decreases that was quite obvious and I struggled for some time to fix just those stitches so I ended up ripping out all my brioche knitting progress and starting it again. I'm back on track now and trying to figure out if I should make the balaclava a bit smaller than the instructions recommend since I have a child's size head or knit as is. I'm leaning towards knitting as is, I'll make another if it is much too big.