In my last book, the Encyclopedia of the Ibeji, the chapter “Ibeji” starts with
a sentence which is already a partial answer to your question. “The Ibeji is not
the portrait of a child, but the statue of an adult”. Your statuette represents an
adult female, carved with all the characteristics of a common Ibeji, but with the
addition of a kid on the back. This is the representation of a mother, or a female
figure clearly compatible with an adult Ibeji. This is a type exceptionally rare.
In fact, it is the second Ibeji, “mother with child” I have seen in all my life of
Ibeji scholar. This Ibeji come from the a workshop of Oshogbo, like the other one
I saw a few years ago.
Clearly it is an Ibeji that has a high commercial value due to its rarity.
But you should be careful. As I said several times, my answer on this site is not
an expertise, because it is based on the analysis of a few photos and not on the
direct examination of the statuette. For this reason, I suggest to submit your Ibeji
to an expert, in order to verify the authenticity of the patina, the sculpture, and
the tribal use.