Could be genuine and if it is, of course refusing it could start it all up again as you said. It seems that her boyfriend does not see anything sinister in it, but then men have a typical habit of never really looking at things too deeply and seeing the real meaning!
I do though see that she is in a difficult situation, by accepting it could put her where this woman wants her and by not accepting it could insult any innocent intention!
Perhaps I am looking too deep to be of any real help!
I think if I was her friend I would sit down with her, go over why it could be genuine, write it all down, go over why it could be sinister, write that all down and then go with the option that has the most or best reasons behind it.
At least then if you disagree with the findings and still try to advise her otherwise it will show her that at least you were prepared to look seriously at all options and debate them. Do you think that could work?