Trouble is the older animals get fat and lazy and don't bother to exercise unless there's some real stimulation. Being intelligent animals they realise their food is supplied by keepers, not by having to climb around looking for it so why bother? Its a sort of vicious circle experienced in nearly all zoos to some extent.
Both of Kibriah's parents, Jod and Twiggy were born in the wild, but both were very obese at Twycross(Twiggy was already obese before she arrived from London Zoo and was another 'football-shaped' female)
I think she was already pretty fat when she arrived from Indonesia(not directly from the wild) so the name was a bit of fun. It became even more ironic as she got older.