What can Ida tell us about human beings?
Ida’s body size, the shape of her body and her way of life are in accordance with what we would expect to find in our common ancestor, 47 million years ago, based on what we already know about the evolution of human beings. Yet, Ida is not our ancestral mother (even disregarding the fact that she died before she could have children). She is rather an ancestral aunt.
We know this because her most anterior cheek-teeth are too small, compared to the ones we see in the oldest and most primitive of the great apes. They would have to be bigger in Ida, if she were to belong to the species which was our direct ancestor.
Was Ida the "Missing Link"?
In one way no, in another way yes.
No: Ida was definitely not "The Missing Link" which should prove the theory of evolution. No serious scientist doubts this theory. The theory of evolution is so solid and has been confirmed so many times that the find of Ida makes no difference one way or the other.
Yes: However, she is nevertheless a new piece of the puzzle and answers several questions. At the same time, she raises new questions; this is how science works. Donald Johanson, the man who found the fossil Lucy in Africa in 1974, puts it this way: - Every link in the evolutionary chain is a missing link until it's found. And then it's not missing anymore.