Re: how to stop her chasing birds and birds?
Chili is still very young, and "slips" will happen. Rabbits in particular seem to fascinate Vizslas.
Chili will naturally put her nose to the ground and seek. It's just her nature. Vizlsa also have some "coursing" genes, meaning they will run an animal down it's back trail to locate it,and can actually be trained to bring down smaller mammals like deer. They can do it very effectively.
Realizing this though is only one part of the equation. Studying the patterns and habits of prey animals is another.
Deer move in straight lines, along "lanes". These lanes are invisible to the untrained eye, but once you learn what to look for you can easily spot them in the woods. Some lanes are "Master Trails" and they are like deer highways. If Chili takes off hot in a straight line through the brush, it's an odds on bet that she's scenting deer.
Rabbits move in a circular rotating pattern. Rarely in straight lines for very long. If her head goes to the ground and she starts running in a circular pattern, back and forth while moving in a general direction, she's probably pottering rabbits.
Turkeys move with a purpose in a zig zag pattern that appears straight, but really isn't.
Upland birds move in an indiscriminate manner on the ground,and almost always in edge cover. They will fly and land and move around like a chicken, If Chili's nose goes down and she stays tight going back and forth she's probably on bird scent.
The key is to recognize what she's most likely after and stop it before she gets too far along.
Should you reprimand her for going after rabbits. Yes you should for two reasons;
One she didn't listen and two you may not want her to hunt rabbits. I don't like mine hunting rabbits or deer, so I "break" them to those two animals. It's unproductive and annoying.
How to do it is the key, and that's why you will need to recognize what she is probably after and stop her as soon as possible and move her off.
It's not easy and it takes time.
You'll never beat a lesson into a dog, you just beat desire out.