Thanks everyone and no, SD, I didn't know about the soft drinks. The last time H and I went was just before we got married, so ten years ago and I don't think soft drinks were that high on our priority list!
I'd really like the girls to see something of the 'real' Paris - am beginning to think we could have saved our money and gone and stayed with Mum in London for a fraction of the price! Rue Moffetard sounds great though, that's just the sort of think I'd like them to see.
The only think that really sticks out in my mind is those catacomb things with all the skulls lined up from when they cleared out the cemetaries (what on earth was I thinking of???) but that may be a little too much for 7 and 8 year olds. And my Eurostar phobia, but that's another story .......