Ginandmanic sorry to hear about your dd1's encounter - I think all clubs/societies can have their cliquey elements, so it may just be a question of trial and error. 4 in a flat is not many (again not a great design), and if those there are are not very social, it sounds as though she may make her friends elsewhere, on the course or in clubs (subject to the above!) Friendships with the flatmates may evolve, but slowly.
This thread has made me wonder a bit about the way things are organised. Freshers week creates this huge emphasis on making friends and having a great social life straightaway, whereas in real life we wouldn't expect to have made a best friend at work, or where we've moved house to, within a week. More like years! I worry that the dstudents feel as though things are going badly if they haven't got an instant social circle, whereas in fact, for all but the real social alphas, it's perfectly to be expected that it will take time.