There seems to be a handful of bird of prey and falconry centres in Cheshire, most of which are quite expensive. Not only is this one reasonably priced £3.50 adults and £2.50 children over 3, it is ideally situated next door to a superb garden centre - Fryers of Knutsford. So maybe kids and parents can have a great day out in one trip.
Http://www.gauntlet.info
Update - we went and I have to be honest, we struggled to stay more than an hour. Really not that great. Too small and you certainly wouldn't stay for more than one display.