Check the Marriotts in Paris. We have a baby ( in a crib) and a 4 year old and we were told that the larger rooms accommodate 4 at the couple of hotels we checked. The larger rooms come with a cash supplement of 90 euro -120 euro. Write to the Marriott concierge desk and they will contact the individual hotels directly for occupancy rules. For what it's worth, Marriott website doesn't list these hotels having 4 people occupancy. Obviously if the kids are bigger that may not apply. We stayed in Italy in 3-4 hotels 3 years back with a one year old and didn't have any problem