When I read Radzinsky's first book I was mesmerized--a Russian writing about Russians! But soon enough his suppositions and flights of fancy began to annoy me. He has a dramatist's way of telling the story--as if you're a small child, listening at bedtime--so while I can't deny that at times he may be correct, I feel that he is much more raconteur than historian.
When it comes to Anna Vyrubova, I think she was simply an immature personality, attaching herself in puppy-dog fashion to those who listened to her and sympathized with her. We know that Marie Nicholievna had this same quality of being as faithful and obliging as a puppy, but it also appears that, for all of her emotional dependency, she was growing out of that tendency and becoming more her own person. In my opinion, Anna was not willing and/or capable of doing so and probably would have continued to have her childlike "crushes" on both the Tsar and the Tsarina for the rest of her life. As it was, she did continue to support them and--within her own limited means--to save them, and after their deaths took on a "Keeper of the Flame" role.