Sole owner on deeds died leaving house to wife after 30 day survivorship clause in Will

My father was named only on the deeds though married. He died in February 2023 and unfortunately my mum in July the same year, some 4 months later. There was a survivorship clause in the will of 30 days after which she inherits all as my dad intended. Does she own the house to sell though not registered? Both probates have been obtained with 2 different  executors for my mum and dad. We are looking to sell the house, so how do we proceed in the sale process of the house if as yet its unregistered as my mothers due to her passing.
Thanks

Michael - I am sorry to read of your loss. As your late Dad was the sole legal owner the property remains part of his estate until probate is granted and his executor(s) deal with it
The will and any survivorship clause is insufficient to transfer the legal ownership 
You don't mention who the different executors but there can be ways forward including
If for example your Mum obtained probate for your Dad, and someone has then obtained probate for Mum, you can create what's known as a chain of representation with both probates. And a buyer can usually rely on those to complete the purchase.
However if Mum was not Dad's named executor then it would be for his executor to now deal with and sell the property. Probate was not needed for Mum re the property as it remained part of Dad's estate as his executor had not transferred the ownership

Land registration is complex, designed to protect legal and financial interests in property. There can be significant consequences for any error. Please consider seeking legal representation. Before making an application without legal representation, it is important to consider the benefits of using a conveyancer.