Thanks for the replies everyone and the suggestions.
I know that friends will be happy to help, this isn't the problem - I think my first post was rather unclear - we are hoping for a homebirth as my with my DD I had a great homebirth.
But I am realising this could be more problematic in terms of childcare, because it means DD needs to go to someone else's house rather than someone coming over to look after her, since our flat is so small - no question of her being looked after elsewhere in the flat.
DD sometimes goes to play next door, she could go there esp if the labour seems like it might be quick (which is what worries me being 2nd time around) - I guess if it was nighttime we could let her sleep but then wait till she wakes up and DH could take her next door - I'm not sure about waking her and taking her to someone else's house in the middle of the night as this seems very disruptive for her and them.
I have close friends who live a 10-15 minute drive away who I would ideally like to ask, they might also be able to give DD a bed as their kids are teenagers and one of them could give up their bed. But they have no car to pick DD up, so DH would need to drop her off and come back which would mean leaving me alone unless we wait for the MW first. (Last time we put off calling the MW and she arrived 1.5 hours before baby did.)
If I went into labour in the daytime it shouldn't be a problem, it's evening or night time that worries me.
DH said that we have to be prepared for a quick labour and not being able to arrange anything in time so that she ends up still being there when the baby is born - I really want to avoid this as I think it would make it impossible to focus on my contractions and hamper my labour.
But I don't want to have to book a hospital birth just because it would make childcare arrangements easier.
Maybe I should ask on some homebirth sites to see what other people did in our situation?