With regard to Anna's feelings toward Sonya Orbelliani , a little reasoned(I hope) speculation. She may well have felt jealousy or envy toward Sonya because SO may have indeed been Alexandra's better, truer friend. She was a brighter, stronger , more accomplished person than Anya and in most respects was a true equal to Alexandra.Alexandra was certainly devastated by Sonya's loss . As noted the friendship between Anna and the Empress was unequal. I can imagine Alexandra might well have valued Sonya's independence and spirit as compared with Anna's puppydog -like devotion. As Sarushka said, it's very plausible. Sonya was, in effect, Anna's rival for the Empress' affections.
