Morning Paul - her death is a very sad fact so the register can be updated at any time and it is often done when there is something else to update such as a sale/purchase etc as you suggest
If you were selling for example you would provide the buyer with a copy of the death certificate to prove her death and explain why only you were transferring the property.
Having now thought about it you can
apply to update the register if you wish but there's no 'need' as explained