Please keep us posted on your ride JC cause Renay and I are considering them . What size did Terrie order? I wear between a small and extra small so curious if the size runs true or smaller or larger.
To be sure, just take a cloth measuring tape and have someone measure about an inch above your eyebrows, around the back where your head sticks out furtherest. The Nolan N-104 sizing chart says 20 1/4"-20 7/8" = XS and 21" - 21 5/8"=Small. If you wear a Doo-Rag under the helmet and are right on the edge of one size or the other, take that into account, depending on what type of doo-rag you use.
I "discovered" this product recently...I have dozens of doo-rags 'cause it helps keep the inside of the helmet a little cleaner, but this thing is by FAR the best thing since sliced bread. Thin, so it takes up no room in the helmet, wicks moisture, no seams, takes only a few seconds to put on in whatever configuration. I have three of them now...one UV and two "regular". Comes in numerous colors/designs and covers up the "helmet head" look, particularly if your hair is longer.