Hat?! I thought you were making the scarf!
Anyway… That’s not uncommon to increase after the brim/edge. Having the edge a little tighter helps the hat stay where it should and it helps with shaping.
If I’m doing the math correctly (102 divided by 12) comes to 8.5. Well you can’t increase on half stitches so just increase about ever 8 and if it’s not perfect it’s fine. What I’ve done in this situation is increase some 8 and some 9. As long as you end up with the correct number at the end it’s fine.
Unless the pattern says otherwise I’d use a M1 to increase. That’s where you pick up the thread in between the stitches with your left needle from the front and then knit through the back loop to tighten it. If you find it easier to pick the stitch up through the back then do that and knit the stitch through the front like normal.