Agreed £6 would be taking the P for that but a student might oblige if you could feed her as well & occasioanlly offer some babaysitting if they were local.
I would do an hour for that if I could fit it in around other jobs/my family.
I have just finished doing this for a family I would pick up the little one from pre-school at 3pm take her home & wait till mum or dad got back. (Usually 2 hrs) I would do a bit of ironing for mum, play with little one & anything else that needed doing. It worked for me as it was literally around the corner from me & if I wanted to pop home to get the washing in/out my charge would come with me & "help". (with parents permission)
I would do just one hour as long as it was every day as I can often find PT jobs at other times -needs must in this climate I will do anything!