Except Auma admits there's no legal records of her marriage to Senior so all Ann had to do was bring along the divorce records with little Barry named and viola! there's the legal marriage and Kenyan citizenship. Then they drag along Professor Alice Dewey of UofH so who's going to question a professor where Senior attended. Interesting timing - after Senior died but before the citizenship timeframe expired.
First, Auma, on the corroborated record, is Barry's half-sister and is the child that Kezia was pregnant with when BHO Sr. in corroborated to have left Kenya in 1959.
The conversation you refer to involving Auma and the estate of BHO Sr. is ONLY sourced to dialog in Dreams which was most likely invented by Ayers and/or Obama (Ayers is quoted as saying he “wrote the whole thing,” IIRC).
Anything in Dreams, IMO, cannot be used as a primary source and is highly unreliable and this “memory” is uncorroborated by any open access Kenyan government or tribal marriage records or access to any family witnesses, IIRC.