My strategy with her was just stick and move. Easiest method for ranged damage is to just stock up on rocks and use the "throw rock" skill as that does a consistent 5 damage to her. As someone else has said you can only really hit her in melee once or twice between attacks, as she can smack you away when she uses certain attacks.
If you just want to fight her at range the little outcrop with the tree that you can reach by jumping onto the part of the pillar and then jumping to it will make it so you don't have to deal with the tar spawns, but it will make avoiding her attacks a bit harder with the small amount of space you got, especially the aoe attacks like the bouncing slime ball and the slime eruption.