Ramadan is approximately from the 20th July to the 18th August (dependent on sightings of the moon. Within this time period you may not consume any food or liquid during the daylight hours in public.
Up to the 18th it might be easier with the kids at the airport hotel.
True, this could pose problems (e.g. many restaurants etc will be closed until evening). However, Dubai is a tourist friendly city and reasonably accommodating of non Muslims. Last time I was there during Ramadan, Costa Coffee shops were open but had screens around the sitting areas so that people could consume food and drink discretely if they chose to do so.
You should definitely check this before booking a hotel though.