Newb Question: How to thin the width of an existing path image
I'm fairly new to illustrator (PS being my stronger application). Can someone please tell me or share a video link instructing the best way to thin the width of an existing path? I'm working off an existing .svg file of a bow and my boss would like me to make the line width the same as the balloon string (pictured below). I tried to recreate but it looked pretty jagged even trying out the curve tool.
.svg
Image:

