This is to present statistics ripped from all context, though - and she is absolutely wrong (deliberately wrong too, given how often she cheerleads for whatever the Tory Party generally and Johnson specifically are saying) to make this argument, however incompetently.
Aside from global wars, we've only rarely had events that impacted as many people as this has and none of those occured in an age of genuine mass communication. We've all seen the impact of disasters - Grenfell, Hillsborough, CJD, train crashes, plane crashes - with death tolls that COVID beats easily each day; even a disaster like 9/11 dominated that entire decade (of course the US are occasionally having that number of dead per day). We already feel (and are encouraged to feel) sympathy for the victims and loved ones of those who died in these horrors even though we are very unlikely to have any link to them whatsoever.
This is however much different - to use your statistics, 3% are going to closely know someone who died in this. That is (and I know people arent distributed evenly) going to mean every workplace of any size above a single shop is going to have someone who was closely affected in it; every full bus is going to have someone who was closely affected in it, Goodison is going to have more than a thousand people in every capacity crowd who are going to have been closely affected by this. We are in short all going to know someone who closely knows someone who died.
... and that is just deaths from people who died. Theres all the people who were intensive care and didn't die, all the people who lost their jobs, all the people who were locked down and felt terrified. As British disasters go this has been relatively universal - we've all been affected to at least some extent by it.
Of course, this means that this has the potential to generate really severe problems for whoever ends up getting blamed for it. The government and its mates in the media certainly know this, which is why they've been working so hard since about mid-February to aim flak at everyone else - SAGE, other "experts", the Opposition, foreigners, the North, the South and (after Christmas) the population who wanted to have turkey rather than protect their own family.