Haringey is quite a varied borough.
Highgate is one of the most expensive areas to live in London (Sting, Charles Dance, Victoria Wood, George Michael, Noel Fielding are or have been residents). It borders Hampstead Heath which is lovely. In fact there are lots of parks all over.
Muswell Hill and Crouch End are also expensive, middle class areas, with lots of those shops selling expensive clothes and overpriced tat, dressed up as gifts. They are not on the tube, which is a disadvantage.
Stroud Green, Finsbury Park and Alexandra Park are both nice areas.
Seven Sisters is a very mixed community. Lovely houses which have been gentrified sit alongside some rougher estates. However, it has a nice, lively vibe and I have friends who really enjoy living there. It is very accessible.
I am not crazy about St Ann's/ Green Lanes, but it has great Turkish bakeries and a friend who is a student enjoys living there.
Some bits of Tottenham are not brilliant.
Your daughter should be fine though; Haringey is not a bad choice. If she does get ill I personally would avoid the North Middlesex hospital. The Royal Free, Royal London, or UCH.
When she arrives she will need to get an Oyster card for the Tube, A to Z, and a copy of Time Out magazine.
One of the things about studying in London is that it is so big and there is so much going on that it can take a while to settle in. There is not quite the Student Union culture that you get in other universities, possibly because you can find so many better bars or scuba-diving clubs or choirs or whatever and because students are so spread out, unlike say Newcastle or Leeds, where there are a couple of areas which are packed full of students in every other house.