Set up your own baby sitting circle with other trusted Mums/carers from school. Worked best with us with about ten members.You print your own tokens and give each member eight tokens, everyone agrees that they will be the sitter ( not partner, aupair etc.) and then have a coffe morning once a month to swop dates for forth coming events. People are free to leave if they 'buy' themselves out with eight tokens (just like they got in the begining) No new mwmbers can be taken on board unless everyone agrees in principle to their joining at previous meeting. One token represents an hours free babysitting.
Problems that you might encounter.
The after midnight revellers.... charge two tokens per hour instead of one after midnight!
Someone with loads of kids versus someone with one child agree terms when setting up framework of arrangement.
Having people arrange sleepovers : then getting you to babysit .... not on - discuss when suggesting the rules to stick to.
Meetings ( we used to have a lunch ) at the begining of the year, pull the names raffle style for who s house the meeting will be at ( easier if the person in charge of the tokens makes a note of this.) Laminate the tokens ,having numbered them under the laminate. Place a punchhole on them so they can be pinned on boards with minimal damage to them or everyone doing something different to them( v. irritating)
If everyone is from the same school this can lead to problems on big fundraising nights, to avoid encourage other members to recruit from other activites maybe yoga class, or a local sister whos kids go elsewhere.
Then have a worry free evening.