Oh goodee we’re again at the stage of the pandemic where we turn our noses up at people wanting to spend their money and free time up in a downmarket way again are we? Yuck, Chessington 
The poor parents and children. It’s so hit and miss when you go out whether the place will be awful or not. I’ve been to one theme park during the pandemic and it was fine - no queuing to enter and average queues for the rides so if it had been me I’d have happily gone to Chessington expecting it to be fine.