Our local lake has a path, about 3-4m wide. It can get a little busy but there's always plenty of space for social distancing.
A few times during lockdown young DC have come within 1m of me/my DC by the lake. I noticed but it didn't really bother me.
Today a toddler, about 18 months/2 years old was running ahead of her parents, very close to other people. They made no effort to stop her, just called out her name in a sing-song voice. We stepped to one side of the path (couldn't go further without falling in the lake!) and she came and grabbed onto DD2's doll. Parents still did nothing.
When the parents got nearer, I said "kids need to stay 2 metres away too". The dad picked her up without saying anything.
DH thinks I am BU for being patronising. I think the parents need to make sure their child is following the guidelines - the parents were both wearing masks so are obviously aware there's a pandemic going on!