Is there a closer hospital than mombasa fred? If she was willing to live in a filthy village, she could have had zero anywhere- i mean she doesnt sound like your typical house wife from the states— sarah might have delivered the little satan in the village hut... who knows..
It's half as far to Nairobi which is a modern city. If 'granny' Sarah was present at the birth of Barack Hussein Obama, that child would have been the son of the first wife of Onyango, her name was Akumu iirc, she was the mother of the kenyan student. And yes, on second thoughts it might be possible that birth took place in Mombasa, but just how the family, which would have comprised of Onyango, his pregnant first wife and his wife number two, Sarah...all ended up in Mombasa at a festival during which time they went to the beach...in 1934 or 1936 (the kenyan student had TWO birth years) seems like a logistical nightmare.