Walnuts - too close

Tried to get up before 6am to walk Murray but while the spirit may be there the body was weak. We made it out before 7am. 
Headed into town, roads still fairly quiet. However, there were more market stalls and people.  People are queueing as if we're not in the midst of a pandemic. I was in front of the cheese stall being served when a boy of about 11 stood centimetres close to my left, equally close behind and to my right was a sibling and mother.  I said they were too close and could they please keep to the 2m social distancing. The child on my left apologised but his mother claimed they were 'only looking' and that they 'were clean'.  They did move away but not without unpleasant words to the tune of 'keep your hair on'.  She didn't conceive that I could possibly infect them.  
By contrast the staff member at the entrance to Sainsbury's was reminding customers  to maintain 2m distancing at all times in the store.  Thankfully people were abiding well to this. 
At home I began thinking how I could respond better to people not observing social distancing.  I think I will state that in the event that I might be a carrier I don't want to infect THEM.