That family unit (father, mother, 2 daughters) left in 1939 out of fear of what he would do. The father had read mine kamph and believed it. He gave up everything and got his family out.
Other members of their family didn't leave, and it didn't end well for most of them. Apparently they didn't believe that hitler would come after german jews. It was the polish jews, and gypsies, and the like, that he would go after. They were germans. They weren't worried. Emigration was largely cut off after 1939. That was a last chance exit, and luckily it worked.
But it wasn't easy, in large part because the us and other countries didn't want jewish immigrants. The us gov't knew what was going on. It wasn't a secret to anyone on this side of the pond. The holocaust was ignored. They didn't want more germans, and especially didn't want german jews. You had to have money, and family who would provide a guarantee. The slots were extremely limited.
But I'll take first ahnd experiences as fact. Sure, it's clouded with anger at times, but the story is consistant accross too many people to be false.