Hit, and run, and when she does Spear, jump + whirlwind if you need to escape!
Ys 6 and Ys 2 allow you to heal during Boss fights. Healing would be too op during such short fights though.
Yeah, i probably should. I really need to let her get her levels at Turn 5/10/15 so i can save scum xD
Don't wanna retry many turns just for lvlups XD