First off, at 12 ,I think its pretty awesome that you've gone on a search to save the cats and help your dog. Good job.
Our young male like to chase the cat. Pick a word,we use "off". Pay close attention to your dog, whenever her body shows she's about to move towards them or pounce, say off! This should be done with a leash and then gently, but firmly pull her away if she doesn't move. Reward her as soon as her attention shifts from the cat to you. The reward must be instant.
I would use a prong collar, fit correctly.
It wont happen over night. Don't get mad at her or allow anyone to hit her or punish the dog. Its her natural prey drive, genetically ingrained in the dog. Some are harder to control. The key is setting up a positive situation where she can win. Maybe leash walk her by the cats, let her slightly key in on the cats,give the "off " command with a quick short prong correction, as soon as she looks away give her a high value treat, something good for her that you may not normally give.
Another key is this is a symptom, a training issue. Take her 2-3 times a week for maybe just 15-20 mins and work with her basic commands. Sit,down,stay,come...rewarding and praise. She'll learn that listening to you is fun, listening gets her cool stuff.