Just that really - we are catching a night train at around 8pm, our Eurostar arrives at noon. I thought we would have lunch near the Gare du Nord, take our bags to Gare du Lyon and leave them there, and then spend the afternoon doing something fun, before picking up some food to have on the train.
They have been up the Eiffel Tower, on a river boat and to Montmartre. I haven't taken them to any of the museums - would the Louvre perhaps be a bit overwhelming? They are 11, 9 and 7....