Despite her enormous DPS, Kirsten has mediocre range and a longer-than-average backswing, making her easy to stall with enough meatshields. As such, she should be a pushover as long as you use Witch Killers or other long range-attacking cats leveled up enough and protect them with smaller cats like the Basic Cat and Tank Cat.
Time between attacks
*In each stage, there is strength magnification, the value of health and attack power varies due to this value.
*Time between attacks is the time of the attack from the motion end until the next attack motion start.