The school has an address in Byng Road and the school entrance is also there. You cannot therefore put school entrance markings in Wentworth Rd as the road does not contain a school. The ziz zag lines 1027 are prescribed for use outside schools, as the Traffic Signs Manual tells you.
A different idea would be to take the existing school roadway entrance and make it wider and create a safe drop off zone within the school grounds which are extensive and which would make Wentworth Rd quieter for residents as a by product.
Parents: a camera will doubtless go up at this location so do not stop on the zig zags themselves.