I personally have never been involved with an intervention but I have heard many stories of interventions gone wrong at my al-anon meetings and also reading here.
When you say those closest to her will be participating – do you mean her friends who she does drugs with? Co-workers where she is a stripper? I know the A in my life’s closest friends were those that enabled him to continue doing the self-destruction of his choice. And the ones who were not drug users he was no longer close with and I know there would be no way any of them would have had any kind of impact on him choosing recovery from an intervention. Addicts usually do not hang out with non-addicts for very long.
Do you have facilities lined up so if she does happen to say she wants help –off she can go right away as in immediately after this intervention? Many will talk a good game then fall off again while waiting for a bed to open up or a facility that will take them? Does she have insurance that will pay for this? If not, what is that plan?
The one mistake I seem to see over and over again with having an intervention is not really having a clear plan other then everyone stating how they feel and the addict responding sure, yes, ok and then walking away right back to what they did yesterday.