Yeah, taking it into AI might help. But on the other side, you have this beautiful, organic line work all around her face that you'd lose in illustrator. It comes from the pen, which your brushstrokes/handworked elements of your art is really your strength. So I might not take it into AI and get a really polished line. But I'd check the balance of the linework--so delicate and almost non-existent around the face, then blocky and awkward up in parts of her hair. Maybe I'd just take it into Photoshop and taper off some of those lines... like the boob line, taper that off so it's not all blunt where it starts, but you'll maintain that hand drawn look that makes the piece.