This is always difficult as everyones experience is so different...
....but have you tried suggesting the idea of helping her to experience sex from a female point of view.
..maybe suggest that to make her feel more comfortable you want her to stay "tucked" for the whole session, and that you will try to exite her without touching "that" area.....say you want her to use the "toys" with you, and she can also try them if she wants.
If she has had an orchi, then she should be getting increased skin and nipple sensitivity (we have some notes on nipple orgasms in the sexuality section), so I would be surprised if you failed to get some response.
....I just think making it clear that a "male" performance is not required, and taking steps to "prevent" it from the outset might help..
I know that I enjoy cuddles and foreplay more with my partner these days, than the "act" ...
Chrissty