Stop the behavior. Reprimand the puppy verbally (for now!) enough to make her understand that this behavior is unacceptable. Escalate the reprimand if necessary until she is neutral to the cat.
I will not tolerate a cat aggressive dog....it won't live with me if I cannot trust it.
Csabre Sch1, Hexe Sch2, SG Bengal, Lynx, Komet, Kira HGH & Kougar v Wolfstraum ~ Ziberia IPO1 ~ ATB Basha, Kougar & Kyra, Fenja, Sch3s, Cito, Sch2, Danger RH & Alice Sch1s ~Kelsey