UPDATE: SUPER HELPFUL TIP WHEN WORKING WITH BRUSHES!!!
I learned the hard way that some brushes have built in opacities. Essentially, this means that while they may look fine on your monitor, when you print them, the blacks will turn grey.
After hours upon hours of trying to isolate the strokes using that particular brush (which I was never successful doing...) I had a friend over who was able to dig through and help me.
In case you ever run into this issue, which you hopefully won't, here was her solution:
1. Highlight the strokes (I am pretty sure we highlighted all of the strokes just in case)
2. Object > Expand Appearance
3. Window > Color
4. Click the drop down arrow in the top right corner and select CMYK.
5. Select the desired outline colour and you should now be good to go!
Progress after Day 1! Played with brushes to get some texture, created shapes with both lines and multiple basic shapes. Next up: learning about textures and trying to figure out this gradient thing (massive first day failure!)
Day 2: Progress! Finally figured out that watercolour and chalk brushes do a great job adding texture when used in different stroke widths and opacities! Yeesh....
Day 3! Worked the flowers a bit more and I think I'm finally ready to move onto the hair. My AI has gotten really, really slow.....I think my file is too big from all these brush strokes!
Day 4: I think I'm avoiding finishing up the hair. It's probably the most difficult part! So instead, I fixed up the dress, adjusted the lines in her arms and face to make them appear more sketched rather than smooth. Maybe I'll eventually figure out how to handle this hair!