Ok, not a very accurate thread title, sorry.
DD1 is 7 in a couple of weeks. She's very capable, sensible, responsible etc. for her age. I often walk her to the end of the road that the shop is on and she goes the rest of the way on her own or with her 5yo sister (also very sensible for her age), gets what she's getting (she always has to get a precise item - no standing and picking and choosing IYSWIM), pays and comes back out. We also do this if we're in the car - I stay in the car with the little ones while she and her 5yo sister go in.
Lately I've been letting her go ahead on her scooter while I walk behind. I've let her cross the roads she has to cross on her own, well ahead of me, and I can see how sensible she is about them (they're not busy roads at all). I get to the shop about the time she's finished paying, and she scoots past me back home while I walk behind. She's much faster at scooting than I am at walking, so she's virtually doing it on her own (or with her sister).
The walk in total is 1/3 mile there and 1/3 mile back.
What should I be worrying about when making a decision about when to let her and her sister go on their own?
I'm not asking for what you would do, just what I ought to be considering, because at the moment, the only thing I can think of to stop me doing it, is road crossing (which I don't think I need to worry about) and stranger danger (at what age do you just accept that this is a danger and you have to just let them go?).
If I let them go on their own, would it make sense to give them a PAYG mobile in case of emergency? Would the 7yo be safer going alone than with a 5yo or vice versa? 5yo is also very good at crossing the road, btw.