I would not be overly concerned, as long as Lexie’s eating and drinking normally for a puppy her size. Some dogs are more outgoing than others, and I bet she will lose her fear in time. Did you choose this puppy from the litter, or did the breeder just have this one available? Of course, some are more outgoing than others (but a breeder would know better from first hand experience) and I would think the shy pups are more often chosen last.
But I really wouldn’t suspect a long-term problem, especially since you are giving her so much love and attention. You may wish to start slowly with he, though. For instance, giver her treats and toys in the place she feels secure until she builds up her trust. And just sitting on the grass when you take her out is not all that unusual at first. Please keep up your efforts and I bet she will do fine after a few more days with a loving family like yours.
