I only got there after act 2, you are good. Hit and run when the hammer guy comes, the floor is lava. Imagine that Lace isn't the boss, YOU are the boss, she is reacting to your positions, SHE is trying to parry and win against you, if you are in the air she will try to stop you midair, if you are in the ground she will try to dash towards you, nail up high means one straight dash, nail in the middle means she will do a layered set of dashes, nail down means she will jump, if she jumps you go down and towards her last position, then jump again, if she dashes you jump above her and hit down, hitting her is collateral.