I find this a little confusing too. I did a quick search to see how old Step-Grandmother Sarah is. In an article about the inauguration she was said to be 86. That would put "Mama Sarah's" birth at about 1923.
If we accept that the age given for BHO Senior on the "Kenyan certificate" is more or less correct at 26 when BHO Jr was born, then he was born in about 1935.
If indeed Mama Sarah, as wife #3, witnessed the birth of BHO Senior to wife #2 in 1935, she would have been about 12 years old. I don't know the marriage customs in Kenya at this time, and perhaps she truly was married at 12, but I wonder. Chronologically, it makes more sense to me that she would have been a wife and witness in 1961, at age 38, attending the birth of BHO Junior. At that age she would have been a mature woman and would have had the experience to be helpful at the birth of a baby. I don't doubt she might have married very young, but I would expect women attending a birth would be more mature.
One more item that doesn't add up quite as one might expect . . .
You need to read up on Luo customs. There are quite a few articles on the net and a Luo musuem with pictures. It may have been quite possible she was a bride at 12. They could have sex with little girls but just not penetrate them. One girl could have multiple guys coming to her hut.They couldn’t penetrate until she was a bride..or some such thing.I just skimmed over it and don’t really remember what I read.
Thank you for the undate on birth days and ages. I think I saw that explained on an earlier FR thread, but cannot recall exactly. One way to spot the oabamnoid agents is to see which lies and forgeries they try to protect and assert are authentic.