Hi Nightingale4 - I am Maria J, the owner of Eddie Catz.
We started our company after the last party in a Church Hall when our daughter was about 3. By the time I paid the entertainer, hall hire, made the food, bought the party bags and everything else I realised there was a gap in the market and we started Eddie Catz. Do consider us (or another softplay centre) as an option. It's basically easier and more cost effective.
At Eddie Catz we offer toddler parties and other parties too - see
http://www.eddiecatz.com/book-a-party/
We have a venue in South Wimbledon and one on Putney High Street.
Good luck!
Maria