How is it that I can agree with everybody here including Pixie? The reason is because everyone living alone is different,
Some people living alone prefer their own company, but nevertheless have many friends. Say they have no relatives, but they probably have a couple of "best" friends who they would rely on if anything happened. They, if they had any sense would keep these best friends informed but would not think or should be expected to keep literally every other friend advised of their situation. Otherwise that is all they would be doing every day!
BUT, people with good intentions like Naomi would worry if she hadn't heard, but she doesn't know that the friend has already contacted other friends, because the best frirends are not in the same circle as Naomi. Therefore as Pixie implies the onus should be on the person worried to contact the person living alone or make an arrangement, whatever, and the person living alone should then explain to the worried one that he/she has made other arrangements in case of problems, but obviously thanking Naomi for her concern.