@Greedybilly
Reassure her with not everyone loves their experience. The first year flats are very hit and miss too, and the stories of people meeting their bff on the first day when they found they were sharing a room are definitely exaggerated in numbers! More often people find their best friends later on, even in the 2nd year or later.
But encourage her to try a few societies. Sometimes the silly ones can be a lot of fun, like a "tiddlywinks society" or "eating cheese" etc because they're full of people who don't really have a strong interest but want to have fun.
I always said to my dc that if they were lonely (or hungry) to join the CU or a local church. They can be honest that they just want friends (or food, I remember a friend at uni saying that the CU had more food than the "Food and Drink" society 😁) and they may end up sitting through a few things that they don't particularly enjoy, but they may also find a group they can run with. Local church either a student one will often offer social events (usually round food!) or a non-student one, may find people feeling very motherly towards her and give her a safety net there.l
My oldest didn't really enjoy uni in her first two years (tbf year 2 was a washout socially due to covid) but loved her third year because she got involved with a theatre group. Theatre's another one where if she can find a group, they're often looking for backstage, whether that's tech, costumes or just shifting scenery. And working together gets a good atmosphere.
Unfortunately I think she does have to put a step out to find friends, but encourage her to know that she is no means alone. And many of the people who on the face of it are loving it, are also screaming inside that this isn't what they wanted.