I don't think she travelled back in time,. I understand that the Native Americans seemed to have sawseen her, and the dinosaur certainly did. But primate-Lucy, she didn't live in North America. Primate-Lucy lived in Ethiopia. If Omnipotent-Lucy time travelled, how is it possible she saw P-Lucy in to-be New York. Native Americans, obviously lived in North America, and Lucy lived in Ethiopa. They could not have possiblepossibly lived in the same area at different times.
Omnipotent-Lucy had to have to remembered them.