From the apparent ages of my grandparents, I would guess that this picture was taken about 1900.
There are two women, unknown to me, on the left of the picture; one of them must be the Assistant Teacher and the other most probably a "Monitress". Monitresses could be considered as trainee teachers and, as such, might well be paid.
Unfortunatly, as regards the children, there is no way of telling who is who; if notes were made of the propsed position of the children before the photograph was taken, these have not survived.