Thank you for your question
My name is Clare
I shall do my best to help you but I need some further information first
Do you have a copy of the tenancy terms?
I am afraid that in general terms there can only be one Succession of the Tenancy and that happened when it was transferred into your mother's name.
There are some tenancies (often older ones) where a second succession is allowed, but I am afraid that they are rare.
You will need to contact the Council for a copy of the tenancy agreement in order to be certain
Please ask if you need further details