I am 26 years old and I have been living in my housing association flat for just over 3 years now. I was given this flat due to becoming homeless after being assaulted by my landlord in the flat that I was previously privately renting and then I found out that I was pregnant. I unfortunately had a miscarriage but I was offered the one bedroom housing association flat and I’ve been here for just over 3 years now. My mum privately rents a house but now that my sister has moved out of the house, she is really struggling in the house on her own financially so I’m thinking of contacting my housing association, letting them know the situation and seeing if she can be added to my tenancy and she can move in with me. My boyfriend and I have been together for awhile and he lives with his parents at the moment but he is in the process of buying his first house which I would hopefully move into around summer time next year. If and when oI moved in with him, would the flat be taken away from me or because my mum would now be on the tenancy would she be allowed to continue with the flat?