Anyone stayed at pontins in particular southport?

[Theresa]

We're going in august and have a chalet for 6 for myself , dh, 2 dc's and my mum. It was a cheapie through the sun, have seen ohter reviews on site that arent great but we've done Haven etc and so now what to expect! However due to a mix up with hol dates (long story!) My 2 nephews are in theory 'home alone' for the last three days of our hol. The choices are my mum goes home early to look after them or my brother brings them to pontins and we 'sneak them in' to use the 6th bed and an air bed. Is this do-able? I know at centre parks it would be virtually impossible, but at somewhere like Haven it would be no problem. What is the 'security' like at Pontins after the initial check in?