rented property, is my landlord aloud to do this?

[kingsdk]

Hello,
Ive been living in my rented flat with my girlfriend for about 10 months now. We are paying 550 pounds per month and paying all our own bills.
The problem we have is the sofas that are in the flat are well past the sell by date toatlly lost all shape and comfort. we have offered to buy our own sofas but she said she has nowhere to store the sofa that is in the flat for the next tennants. She then said she has inherited a sofa from a dead relative and she is going to give us that one anyway. In the 10 months we have been there we have made it our own adding bits of furniture etc. we dont want a sofa that she wants to give us we want some say, theres a good chance the sofa she is going to bring us wont even fit between these bookcases that we bought which fit exactly either side of the current sofa.
Is the landlord allowed to just give us furniture she said shes inherited? prsonally we dont want them. I understand she is looking long term and the offer of a free sofa is of benefit to her. But we dont want a sofa that wont go with anything we have purchsed in the 10 months we have been living there. We are planning to stay in the flat for atleast another 14 months. We want to buy our own sofa to take with us when we leave and to have some comfort in the rest of the time we are there.
She seems pretty adament we cant buy our own sofa we are good tennats have always payed rent on time and shes happy we keep the flat clean etc.

I would appreciate any advice
Thank you