Student tenancy advice

[Krabapple]

Hi. Can anyone advise on this situation please until I can call shelter tomorrow? My daughter stayed in after uni so not actually a student now but lives in a flat in a complex mostly filled with students in a July to June 12 month tenancy.
She lives in a small 2 bed with another girl in the same position, kitchen/living room are one space with a bathroom & both bedrooms leading off. Not a very big space, crap landlord and a bit of a dump but she is stuck until the end of June.
Her female flat mate (Who she didn’t know before but did go and meet) has just told her she has got someone to take over the tenancy. It’s a bloke who my daughter knows nothing about, never met and she has been told he is moving in on Wednesday.
She is very uncomfortable sharing such a small space with a man she has never met.
Is there anything she can do about it? I can’t find if she has any rights? I think she would feel at least a bit better if she had met him. I am not even sure there are locks on the doors.
She had lived in a mixed shared house before but they all knew each other before. I think it’s the idea of it being a total stranger.
Can anyone advise?

Is it let as a whole flat or separate tenancies? If the latter she doesn't really get a choice because her tenancy is independent, my dd is in a flat of 8 and 5 are male, she knew none of them, normal for student pets

It’s separate tenancies. She would be fine in s as shared house with work a few people. It’s such a small flat that’s the problem. As I said, a single space with kitchen/seating area & both bedrooms & bathroom leading directly off. She has lived in mixed halls & a mixed shared house before. I think this feels a bit different as it’s such a small space with no real privacy. Whenever she has shared before she had as had some knowledge of the people before as well - even it was not through s joint messaging group. She had no idea who this is or how her flat mate knows him.
It isn’t a student house - it was just the best way to describe it in the title

Sorry for terrible typos. I hope it makes sense.

He may be lovely.

It makes complete sense.
Unfortunately, as they have separate tenancies then she has no recourse. She either needs to find somewhere else to live or put up with it.
There are pros and cons to split tenancies. Pros - she's not liable for a roommate, one can leave without forcing the other to leave, if one person stops paying rent the others aren't liable.
Major con - anyone can replace anyone and the people living there have no say.

I didn’t think she would have much come back. Yes he may well be lovely - she has plenty of male friends. I just think she feels uncomfortable sharing such a small space with him. She knew her flat mate was trying to get out of her tenancy (moving in with partner) and asked if she could meet anyone first. She has just had a text today and he is moving in Wednesday. She is going to email the letting agent anyway just to check it’s all legitimate. I suspect it’s just an informal thing her mate has set up with someone. If that is the case then hopefully that will put a stop to it.

If it's via an agency I doubt her flatmate has told them as they'd need to take up references and guarantors etc. Get your DD to call them as otherwise it's probably being sublet illegally.
Presumably you're a guarantor so you could call if she doesn't want to as you need to know the risk you're being exposed to. He may be lovely but equally he could do damage that you're left dealing with.

She has emailed and they knew nothing about it and are investigating. I think it was going to be a dodgy sublet. It turns out she does vaguely know him (just from student socials) so it wasn’t going to be a complete stranger. She has now at least got his name & spoken via SNM. She said he did sound nice.
He has messaged to say he can’t get anyone to help him e tomorrow so I think it was all being done on the side & may not actually come off now.
If it does it will be a free weeks for them to check his paperwork and get some locks put on. It will also give her change to meet him. Thanks for the replies