How can I help my daughter to see her bf's true colours?

My 19 year old daughter has been madly (!) in love with a 22 year old narc for nearly 2 years. He bowled her over from day 1 and charmed me and my husband too. Only my son (17) saw through him immediately, but we didn't believe him!

This N even told me straight out once that he can be narcissistic and that he doesn't like being ignored! This got me reading on the subject as by this stage, there were quite a few alarm bells ringing...

Our only saving grace is that it is a LDR-however he is in almost constant contact with her every day and whenever he comes to stay (which is often), it is chaotic and difficult to get him to stick to agreed on dates.He really makes himself at home too, overly so!

My husband and I have read Lisa's books and they were a revelation right from the cover pictures as the poses are carbon copy!

A psychologist who has a special interest in Narcissism confirmed our suspicions and suggested that we do not stop her from seeing him, but that we no longer need to have him stay with us-he does have family who stay quite close to us.

This situation is so tricky as we don't want to alienate her or stifle her as she is now at university, yet we have to support her and help her to become aware of the existence and dangers of NPD.

The last time he emotionally abused her, she managed NC for the first time ever for 24 hours. For that day, she was herself again and told me that she felt strong and good about herself. She wanted a week's break but he got to her quite easily using emotional blackmail.

Do we take the plunge and give her "It's all about him" to read now before the next traumatic episode or when it happens again?
I showed her the cover and all she said was "I'm not subservient".

The rest of us are not communicating at all with him (It's been about a month), but he has emailed me a very friendly and chatty letter 3 days ago which is all about him and bombarding me with questions which I'm sure he already knows the answers to.
I suspect he is about to try to set up another visit. I have not responded.

We feel like we're walking on eggshells in our own home around our daughter as she really is in Lala land, yet, to her credit, she is enjoying her studies and has made new friends.

Please help, any input on this can only help :)