I think it is up to you and how you feel about it. If you decide against it, would your daughter be unhappy with you.
A lot of grandparents are already doing similar things and not getting paid but do you want to be tied down looking after someone else's children and not free to enjoy what you want.
I think I would do it in the short term but not if I was tied down for years taking them to and from school etc.
The amount of £700 per month would not take you into the tax bracket and as long as you pay for your NI stamp every week then it would be basically cash in hand.
Do not be pressured into this, only do it if you want to.
Are You Finding the Hot Weather is Making you Short Tempered?
Speculation: Who Will Be In Burnham's Cabinet?

