sewell is a major theorist for ethnicity and also talks briefly about gender in regards to boys achievement, gillborn, murray and flaherty
social class = douglas, bourdieu and oakley
gender = you can just say feminists would argue since it is primarily them who are critical. but barber, mitsos and brown for gender (boys), mitsos and browne for girls coursework as well.
it doesn't seem like a lot but considering a 30 marker, you'd only need two theorists in your main body paragraphs and then an opposing view for evaluation x