Maybe Clarke started to draw cause now she feels free. She draws flowers, landscapes, animals... but what if one day she realizes she's starting to forget details of him? She's starting to forget how his eyes look when he smiles, if his lip scar is on the left/right side or the way his messy curls fall in his face, so she starts to sketch him. It's the closest thing to see him and gives her hope cause she knows that someday she'll be able to see his face and draw every freckle in the right place
WHO GAVE YOU THE RIGHT TO KILL ME WITH THIS HEADCANON??