If she is financially dependant on him then she may be able to bring a claim under the Inheritance, Provisionn for Family and Dependants Act, but as a general rule the answer to her suggestion is No.
I offer my condolences to you. I'm sure you really need her right now. When my Dad died, he did not leave a will. Everything went to my Mum. It is called "In Testate". It should therefore go to next of kin.
Standard intestacy laws apply as there was no will - Family Dependats Act would probably not come into effect unless there were children involved - the estate would revert back to next of kin - mother and/or father.
My condolonces.