Tennant moving room in house

Hello OpenRent Landlord community!
I have a tenant that would like to move from a double bedroom to the ensuite bedroom within the same house. The rent is more expensive for the ensuite and she is only 1 month into her 6 month fixed term contract. Is it possible to confirm an increase in rent via email and keep the same contract? She has agreed to the price over whatsapp. She would prefer not to commit to another new 6 month contract and i am not sure if we can mutually cancel the current contract to make a new one for the different room?

Any help is very much appreciated, thank you in advance!

If this is a room only tenancy then no, it would need to be a new contract. You would need her to surrender the old one at the same time that she signs the new one. You could also do a deed of assignment, but this could be more complicated than its worth.