The Bering Strait hypothesis does NOT state that all humans came from Africa. It claims that humans crossed the Bering Strait during a glacial period and migrated to the Americas. The theory that all humans migrated out of Africa is the African Origins theory (or "Out of Africa" theory).

Also, the Bering Strait hypothesis claims that the migration from Asia happened in ca. 15,000 BCE and followed the retreating ice sheets. This is contradicted by modern genetic and archaeological evidence. Not only are their burial tombs that predate that by millennia, but there's also evidence of boat migrations to the coast as well.

But kudos for taking the time to pedantically explain to the author the nature of human migration and what her ancestry is.