If you only did one day a week then they would have to find somewhere fir the other 2 days, not ask her oarents to cover fir that too. Clearly it’s not the cost of care if they are both in good jobs. There must be nurseries etc within half hour drive, what will happen when she goes to school. That will require getting her there and back or us transport laid on. Either way pre school children need to socialise and a nursery would provide that opportunity. . I know Canada is big but Surely there is a town somewhere where they shop, see a doctor/dentist, buy petrol, have a meal out? School, church, nursery?
They, not you, are responsible for their child’s care and if you are finding it too much they will have to sort something else out.
I would be very upset if I wasn’t trusted to drive my gc, I know my dd is nervous if we do, but but has to accept it as necessary sometimes.
I suppose they may think you are seeing enough of your gd as you are there 2 or 3 times a week, but it’s not the same as a social visit when parents are present. When or if you stop/reduce the child care would hope your son woukd ensure you still see them all anyway. Be brave, have a chat and stick with your end plan. Good luck.