Actually, there are some standard ways of dealing with these fears. Making it less intimidating, making it different, and practicing to desensitize youself are among those things that are standard psychological tools. Understanding where the difference is between not trusting your partner and a general distrust of the act itself will help her heal. The basics of overcoming these sorts of fears is that she must be in control. This is nothing to do with her current partner, and everything to do with her need to be safe. While each person is an individual, somethings do not vary.

Men who use sex to abuse do so to humiliate and control. No matter that he is a unique individual, the factors of his dysfunction are the same.

Each woman who is abused has been humiliated and controlled. The woman is unique, the factors involved in abuse NEVER CHANGES.

In time, she will definitely find a position more suited to her pleasure. You have found one suited to the pleasure, because you didn't have psychological factors involved. The things I have said are based upon basic principles of how abusive relationships operate. I can almost guarantee that the men who abused her using anal did NOT use lube. It would be considerate of her, it would allow her to think her pleasure (or lack of) mattered. Which, according to the principles of abuse, no abuser would tolerate.

I'm not being argumentative, and there are wonderful wonderful other ways to do anal! I am simply explaining why I gave the specific advice I did.