Hi there, sounds like she has CIN3/severe dyskaryosis. I had this about 8 years ago and from the brief letter I was sent was absolutely terrified.
Please tell her not to start googling as it can scare more..
Basically, CIN 1, 2, or 3 relates to the depth of the abnormal cells. Having Cancer in the cevix isn't something as black and white as having it or not really, like your cells suddenly go really bad as many might think, rather that you have some abnormal cells, and the measurable depth they go to defines the CIN 1, 2 or 3 which are "pre" cancerous, because they are not as deep as what is termed to be the start of cancer IYSWIM.
She does not have cancer, as the cells are not that deep. And they might never have proceeded to have turned cancerous anyway. But just in case they might have, this is why smear tests are wonderful and lifesaving.
What will happen next is she will go for a colposcopy. It's simple although sometimes uncomfortable procedure and 10 to 15 minutes. It's like having a smear but they will put acetic acid (like vinegar) on the cervix. This causes the cervical cells to fill with water so light will not pass through them. They can then study the depth of abnormal cells using a colposcope with a bright light to view your cervix.
Depending on what they find they might take a cone or "punch" biopsy, I had the latter and it did hurt a little. I bled aftewards, so tell her to take a pad in as the maternity pad they gave me was quite bulky and rustly!
The outcome for me was being called back for a loop diathermy, which is rather like a hot wire that burnt away the bad cells. They used lots of local anaesthetic, and it was uncomfortable. But I have had clear smears ever since (and two children, one vaginally) which is wonderful. She will be referred for yearly smears after treatment anyway.
Wish her luck, and maybe go with her for a but of hand holding, I could have done with that.