Your pup is stunning!!! Congrats!! I am an advocate for prong collars, I couldn't wait to get a prong on my girl. However, I did wait till she was 5 month's. I hated the way she pulled against the flat and choked herself. And I really don't like choke collars, they work too much on the trachea, and most dogs don't respond to the noise the choke makes when you make a correction. I work for a trainer, we always start the dog's in chokes, and move up to a prong if the dog doesn't respond to it. Our program is notorious for building up confidence in dog's, and strengthening dog and owner bond. We've had dog's start class basically peeing themselves they were so nervous about just life in general, and by week 3 our trotting around class with their heads and tails up, happily. Most of these dog's in a prong collar. So, I love a prong collar used correctly. But, I don't think I'd have one on a 12 week pup. I don't think I'd be doing anything but positive motivational imprinting with a 12 week old pup. Thats just me. That being said, your pup looks very happy and confident, so whatever you are doing is working! Good luck with her keep posting pics!!