Hi Lisa,
Here is where you will find a list of all your local registered childminders www.childcarelink.gov.uk/
As it is after school care that you are looking for then yes you should absolutely be able to find an after school childminder for 2 days a week. I look after a 6 year old little girl 3 days a week for 2 1/2 hours after school.
As your daughter is 5 and either counts as over five or rising 5 (depending wether she is in reception or yr 1) then it would be no problem for her to go to the childminder 2 days a week in the holidays. Once again I have 2 children who have a school holiday contract that only attend 2 days a week, their mum is also self employed and needs the time for meetings.
I would also be expecting a contract for only the hours you use in your circumstances.