If you are happy to be thought a miserable old biddy who hates children enjoying walking on your wall, then yours is the note to put up, Gabriella, but the OP is the one who would have to live with that reputation. She sounds a nice person who would normally smile at the children and the adult with them if she was in the front garden.
As the OP has watched the increasing number of fathers lifting their children up onto the wall, she is likely to see any further budding mountaineers and their doting daddies.
Is it me or am I getting mixed messages
Son on rebound - wants to marry