Please tell your friend not to beat herself up over it. Even with a megga fertile young couple there is only a 50% chance of pregnancy in any given month. Tell her not to even go there mentally.
YOur friend needs to keep going. DE is not a magic bullet. You just keep going till it works.
It might work the first time (did for someone close to me) or it might take ages like it did for me (6 years). Or your friend might get pg next cycle.
Only thing that is certain is that she had a good chance IF she is cycling with DE.
It sounds like she is on the ball with the steroids and so on.
Just keep at it.
You are a good friend to write on her behalf, best to you and her, THK