Wow thanks for all the responses, it's been very very useful (I'm the OP).
Fwiw at the moment dd1 aged 10 in year 6 does the following and I'm begining to wonder about dd2 aged 8. They are both very sensible girls more mature than me sometimes .
Walk to school (assuming fairly close and no major roads)? Has been doing this since year 5 with friends, but will have to start walking back from school with dd2 due to a change of circumstances. Home is about 500 yards from school and although there is a busy road there's a lollypop lady. I will get home about 5 minutes later, so they will have to let themselves in. It's making me nervous, although I was doing this when I was 8.
Be left at home for short periods? I've been leaving DD1 at home for about half an hour for about six months, recently I've left dd2 with her for the same time while I take ds to a club. They prefer it, I'm confident they are fine and know what to do in a crisis. I felt a bit judged when another parent asked me where they were the other day.
Make a cup of tea? DD1 has been doing this since she was 8, DD2 burnt her hand when she tried and will be using this as an excuse for years to come. We've since bought a new better kettle, but she doesn't want to learn.
Go to local shopping area with friends including short bus ride? Not at this stage yet, but with secondary school around the corner I wanted to get an idea of when this is likely to happen.
Have a mobile phone? She got one for Christmas, it would have been when she started secondary school but we moved house recently so it's been a good way for her to keep in touch with old friends.
Have a tv in their bedroom? Yes and no - she has a tv, but no signal so can only play videos/dvd's when we allow. Last night for example the three dc's watched dvd's in her room as no school today (and was looking forward to a lie in).
Have their own laptop? hmm, we are not loaded but do have an old one since dh was given one at work. We could let her use it if she needs to at secondary school next year - but don't want her to be spoilt.