[foxyroxiesmom]

I recently had to move in with my sister who has 3 cocker spaniels 2 pups that are sisters and 1 year old and 1 old lady 10..My little girl gets along with my cocker - he is 10 and the brother of my sisters older cocker - and 2 of my sisters cockers.
For some reason she stalks and then attacks one of my sisters cocker pups - they are 1 but gets along with the sister and older dog. Why would she do this and how can I correct it? She has never been like this and for some reason she has zeroed in on just my sister's one pup Amber. When she does attack I reprimand her and put her in the crate for about a 1/2 hour.
Has anyone else have or had this problem - Can anyone help?::::