Well the 'G' measurement is European - they do not do Ds ad infinitum, they just go to the next letter - so a DD to them is an E, your wife's DDD is an F - so my wife is one cup size bigger than your girl - probably not even very noticeable.I suppose it has to do with volume - and yes she would like them to be a little smaller, but she is relatively tall and full bodied, so they help keep her propor