A lot of people have made reference to a modern, post-war perspective of Hitler, but AF's initial impressions of Hitler would have been of the populist leader, I think she'd have been far more inspired by his virulent opposition to socialism, then his anti-Semitism.
If, in a hypothetical world, AF had gone into exile, and lived into the 40's, she'd have probably been living in Britain, where many of the elite were in favour of Hitler, prior to the war, and naturally conservative, she'd probably have shared these views. It is possible that her perception of Germany may have changed also, she could even have been living in Hesse, depending on her circumstances. AF tended to look at Germany from the perspective of a nation ruled by a man they despised personally and politically. After the Weimar years, she may have looked at her home more favourably, especially since they were able to retain their properties. Links made by the house of Hesse during this period between the House of Savoy, and the Nazi party memberships, may also have increased her favourable views of Hitler. AF was also undemocratic, to say the least, and charmed by symbols and ideology; many things would have appealed to her about Nazi Germany.
However, these would have gone right out the window once Hitler made his early treaty with Stalin, the rest of the war, including his horrific invasion of Russia, would only have served to horrify her. In spite of being an anti Semite, married to a man who ruled over the pograms, the final solution, and their methods, would have disturbed her greatly. She'd also have been hysterical about their extermination of the disabled, in particular children, as she had a preoccupation with giving care.
I also feel that as soon as Britain entered into a war with Germany, she'd have fallen back into her old anti-germanic boots.