Pretty much equal to me. 18 wears him off similarly to 17, but I think Piccolo would find the right opportunity to hit her with the Gekiretsu Kodan and win the fight. She might not be caught up in the blasts that forced 17 to put a barrier since she seems more careful when fighting, but she also may have been caught on it, dunno. Overall, similar to how it went with 17 and like if the fight kept on, I think Piccolo with huge difficulties would off her with the attack he dished on Cell finding the right opportunity to make her unable to dodge it. How to, though, would be tough. Since she can't detect energy, maybe Piccolo could trick her but unlikely as 17 saw the urgency in dodging it. Piccolo would need to feint an attack while having it charged ready to fire or attack her, fazing her in a rushing way to the point he can hit it home when she's a little off guard. Extreme difficulties for Piccolo anyways.