Sorry to hear this mate, it’s defintely not legal at all so keep those texts and all the photos you took and make sure you pursue it as it’s not only harassment but breaking the tenancy agreement by the sounds of it, won’t go down well in a court of law for her either considering your conditions which she was aware of.
This is part of the reason I still live with my folks as a single fella the price of renting a house/flat is far too high if your living on minimum wage which leaves you with the only option of doing a house share which I did a few years ago and that’s when I realised how many fruit loops are out there. I almost got stabbed by one Polish tennant after his missus accused my missus of stealing their cutlery which clearly wasn’t there’s, had another tennnent that would constantly try to mooch off me and eat our food and then a completely strange Spanish guy called Miguel who had the weirdest eating habits such as microwaving an entire turnip then pouring cold curry sauce all over it before tucking in and the small talk he tried to make made he think he was possibly a closet serial killer. I won’t touch a house share now as it just never works out.