My 2 month old puppy is trying to jump the barrier to our top garden. I say no and remove her but she’s stubborn.
Use a leash and don’t allow her in your garden unsupervised. You’re wanting to offer her freedom in an environment where she’s letting you know you can’t yet trust her in.
The word no doesn’t have meaning to young puppies, and all you’re ultimately doing is reacting/reinforcing the unwanted behaviour, no matter the words you’re using, rather than preventing the behaviour altogether.