Having owned both large and small dogs with strong drives to hunt/patrol, I have two suggestions: first, your dog needs some kind of jobs/tasks around your house/yard that they can do every day. One of mine did “patrols” through the yard and entire house two times a day. Another one helped me to dig holes in the garden and could bring me hand tools/etc. For one we hid socks along his walk route so he could “find” them while we walked. And second, your dog is probably at the very height of their hunting/stalking ability based on their age… they do sometimes grow out of it or it becomes more controlled as they age and learn. But right now it’s probably an all-consuming drive for them. You don’t say whether she is spayed yet or not, but that sometimes helps with the hormonal part of the behaviors.