I would encourage my 11 yo ds to offer himself as a mother's helper but wait on the babysitting until 12 or 13 - and even then it would depend on the situation. I have three children very close in age and I have found that it takes a mature 15 year old to care for them well. One child could be okay with a younger babysitter - but even then it depends on the child. When things are going well it is fine - but what if there is a fire? Or someone strange comes to the door? Or any of a zillion other possibilities that rarely happen but if they do, I want to know our babysitter can handle it and my experience is that
most 10-12 year olds aren't ready for emergencies.
My 11 yo ds is amazing, kind, thoughtful, mature, loves to help and play with younger kids, but I would still want him to have an adult nearby to help quickly if things got beyond his ability to cope. As mature and responsible as he is for his age, I am his mom and I know that he can still get overwhelmed and I don't want to put him or any children left in his care at risk in any way.
When he took the babysitting course last winter (ON) the Red Cross instructors recommended that all of the kids take it twice before actually babysitting. Knowing how much information slips out of a growing child's mind


, I would feel better knowing anyone who was caring for my kids had cared enough to make sure they really knew the stuff they had been taught.