(i) The line that suggests that the child is afraid of snakes is 'I saw a snake and ran away...'
(ii) The line that shows a change in the child's attitude is - 'I’ll stand aside and watch him pass,
And tell myself, “There’s no mistake,
It’s just a harmless garden snake!”'
(iii) The mother is referring to the garden snake, saying it is the harmless kind of snake.