KDA is good, Ahri has fairly low objective damage requirements so that's good, Champ damage could be higher for an S but should be okay for the game length, vision should be higher (you're measuring against people who keep most of their Blue Wards up all game), damage taken should be lower for an S, and CS should be higher.
Keep in mind that for S and S+, you're not just measuring against the average player. You're measures against players who are already good with that Champion playing games where nearly everything goes in their favor. Keep at it, ward more, dodge more, and if the game drags on, don't forget to pad your CS by wiping out waves here and there, in shorter games CS requirements are disproportionately lower. Unfortunately you have to be greedy when you're measuring against players who snowball, roam to another lane for kills, and leave nothing for their ally, so the requirement goes up fast as the game goes on.