18-week old border collie showing signs of fear

[NellsMom]

Hello all! I have been reading this board for a while, and have found the posters’ advice invaluable as I raise my new border collie puppy!

My pup is about 19 weeks old and is a joy — she’s smart, sweet, beautiful, and generally very obedient. After she got her parvo vaccines, I very gradually introduced her to the larger world. This has included occasional short walks around a quiet block, sitting on our porch watching people and dogs go by, playing extensively in our quiet, relatively secluded back yard, and introducing her to only a few dogs that my husband and I know are trustworthy and polite. 

However, she has begun to bark or growl at humans as they approach the house (especially when she is surprised by them) and will bark at other dogs or noises/movements that seem suspicious to her. We live in a place with a lot of foot traffic and dog walking about 50 feet from our front door; if we are outside, our puppy will occasionally growl at dogs (and more recently, unknown people) when they are approaching her from a distance (we try to give her space and not let anyone get too close if she isn’t digging it, but being outside for the bathroom or on the porch means that she can see/hear people and other dogs approaching!)

To address this, I have been trying to keep her within her “threshold” and have been giving her lots of nice treats when she shows signs of fear (like if she hears a dog barking from a distance while we are playing on our back yard).

I don’t need her to be a social butterfly with other dogs, but I do need her to be polite to dogs and people, and I especially want her to feel safe and secure enough with us that she isn’t moving through the world fearfully. Ultimately I want to be able to take her hiking, to the beach, etc, so having her not feel afraid would be very helpful.

I would love some advice from all of you, the experts, on how to handle her mounting issues with fear and anxiety. I have read many of the other posts here, but they seem to pertain either to rescues who may have had bad experiences or 9-week old puppies who have just come home. Does anyone have practical advice on how to address this problem in a puppy in her formative months, without overwhelming her or making the issue worse?