Anti Social?

My girls like watching the other dogs and their owners from across the pond but not too fond of being in the mix. Sable, my Lab mix, is quite the social creature yet she prefers to stay close to Lucy. Lucy seems nervous with a lot of dogs around. That was the point in taking them to the park in the first place as puppies, to get them to interact with the others. I was taking Lucy before I got Sable still she's a loner. Like a parent watching their children and wanting them to have friends and fun I feel as though I have failed some how. Maybe they are just being like me. I tend to gravitate to one side of the water every time I go but I tell myself it's because the early morning sun will be to my back.