@Sara143 .... welcome to BoneSmart. I'm so sorry your mother is having these shoulder problems and it must be especially difficult for you being in another country. My heart goes out to you both.
I took a look at the report you provided and a couple of things stood out to me. She has some tears in her tendons and muscle issues that may require attention in addition to any damage to her shoulder joint. Many times when this type of damage to soft tissue occurs, a Reverse Shoulder Replacement is done rather than a Standard Shoulder Replacement. Either of these procedures can be very successful, providing the surgeon is experienced and has done a lot of them. I also noted the report indicated she has rheumatoid arthritis and this could have caused the loss of cartilage in her shoulder joint, which would give her a lot of pain. If the cartilage is gone, the doctors are right that a joint replacement is the best treatment option.
I had a Standard Shoulder Replacement 5 years ago and my shoulder functions very well. As I said, these surgeries can be key to giving a person their life back. If it would be possible for you to be on a Zoom call with her surgeon, that would probably help both of you be more comfortable with whatever she may be facing. I'd check into that, if you can. That way you could ask questions as the surgeon discussed her case.