Information from the International Office website: Partners and children can pay to become members of Warwick Sport. A number of membership schemes are on offer for the various sporting facilities available, from aerobics classes to rock climbing, swimming to fitness training and much more. Family cards are available. Children under 6 do not require a family card.
It should be noted that University sporting facilities have not been designed with children in mind. There are not currently any sports classes for children on campus. However, the city of Coventry has a Sports Centre in nearby Canley (approximately 1km from central campus) providing a range of sporting facilities and classes. See the Family membership offers at the Sports Centre