She is slower than the original Mooth, but she has higher health, longer range, and the ability to weaken Cat Units. She loses the 1-knockback characteristic of most of Mooth's variants.
Using Kotatsu Cat is a very viable strategy to stall and weaken Sister Lione. Also, Lizard Cat and Crazed Lizard Cat both outrange Sister Lione by 25. Thus, they should be able to quickly deal with her when paired with Kotatsu Cat. She normally acts as support, hiding behind the frontlines. Therefore, Long Distance Cats or Wave Attack Cats can focus on her while other units deal with the front.