Welcome!
First off, remember that she -is- only 3 years old. The range of age-appropriate attention span in toddlers encompasses some pretty flea-sized focusing. That she is absorbing quickly and easily suggests that she has adequate attention for her current needs. In addition, it may be that 1) she finds too many things interesting to stay on one for long, 2) everything comes so easily that she hasn't had much practice applying effort, 3) she prefers figuring things out herself to having someone else teach it to her. All three were relevant in our case.
Familiar, yes, grow out of...sort of. Our child who was most like this is an adolescent now, and is much better at focusing and application, but still prefers discovery learning to transmissional learning, and retains a vibrant enthusiasm about, well, nearly everything!
