Thank you for your response.
Unfortunately, these things are all about paperwork. In regards XXXXX XXXXX Will, these are not documents which are filed with any government office in the UK. Rather, they remain in the possession
of your mother and the solicitor who drafted it for her. The solicitor is not necessarily the executor of the will. Your mother would choose who she wishes to be the executor and state that in the will. In short, you need to find the actual Will in her documents, or some document pointing out what solicitor she used so you can get a copy of the Will from him/her.
The same is true for life insurance. You need to be able to find a copy of the policy information in order to make a claim with the life insurance company. There is no database you can search to determine this. You have to get ahold of either the policy itself, or a premium
invoice that would list the insurance company's contact information from whom you could get the necessary information to file a claim.
This is really not something you can handle by remote control. If your sister is not in the proper frame of mind to be able to complete these tasks and there is no one else to do it for you, then this might require a visit to the UK to handle yourself.
Please let me know if there is any more information I can provide you.