Nope, only in the mindset of a western Christian society. Obama Sr was a muslim polygamist. Therefore he had MORE THAN ONE WIFE. Obama Sr’s biological mother left when he was a toddler and was raised by Sarah (the ‘grandmother’ who witnessed Sr’s birth) who was Obama Sr’s FIRST WIFE and Sr’s SISTER WIFE.
The problem is when westerners like us try to make sense of a society that we do not understand or experience.
Well, since I am from a western Christian society, I’d call her his step Grandmother.
Step Grandmother sounds like a better and more fitting title, but it also explains how she could have witnessed Sr’s birth.