No head collar until she is at least six months old as muscles are not developed enough and damage can be caused.

Lead walking can be a pain, but the most effective way with puppies is simply to stop walking until the lead goes loose then set off again. Stop and start is a useful way to show them what you want.

Are there any fairly quiet roads near you that have wide pavements? If so, try to gain as much distance from the car as possible with you between her and the car. When you hear a car approach either play a game, fuss or give tiny treats until the car has passed. Again, this often works for young pups

I'd have a read of this by Sophia Yin

https://drsophiayin.com/blog/entry/a...erous-or-safe/

I tend to agree that they are fairly safe. However, young pups muscles are not sufficiently developed to withstand the stresses and strains that older dogs can.

If you watch a dog wearing a head collar you'll see that the head is moved to the side when they push forward. In older dogs, the neck muscles are sufficiently developed so they are unlikely to suffer from this, but for a very young pup who runs hard into the lead, that jerk to the side isn't as safe.

Ok I used a head collar on Syd my male Dobermann at 17 weeks for maybe a month till he understood walking to heel, big breed puppies are muscular even as pups and there should be no yanking on a head collar ever. The whole point is to guide and nor should they be running to the end of the lead.Which is actually why I said to use the harness in conjunction with the collar, hold her on the harness and guide her with the head collar. People leave training too late in so many cases and end up using a head collar for life because it magically works, well it doesn't work if when removed the dog still pulls.