It is really important that you draw the lines where you want them to be. Not wanting to look after your GD is nothing to do with not caring/not loving etc. It is entirely reasonable that you want to build a happy relationship with your granddaughter over the years looking after her twice weekly. Other than that, I assume you would happily do extra in a real emergency. But for the rest it is also entirely reasonable that you want your own free time, other things in your life etc.
I think you need to be clear and say that you love the 2 days regular childcare but it is tiring and can't manage extra unless it is an exceptional emergency. And stick to it.
Yes, Why Are SUV's Getting Even Bigger?
The media are already after Andy!


