Can a will be changed?

Thank you all for your help. It would be great if we could ask our cousins questions. We do but they don't answer them. Its a lot to do with her estate - we knew she was wealthy but never asked or bothered her for anything. We used call her and write to her. She was happy in .her own world - living with her junk and her years of hoarding - Then she called me and asked me to call her solicitor and make myself known to him as we were family and she wanted to change her will.