london britain prince george great-grandson queen elizabeth third-in-line throne start school thursday without pregnant mother kate support suffer severe morning sickness george take father prince william kensington palace home thomas battersea school southwest london say important rule kind charge almost 18,000 pound 23,490 per pupil per year expect pupils make impressive progress result hard work best efforts teachers judicious support parent encouragement peer school say website nervous-looking george wear school uniform dark short navy jumper red trim hold father hand head low school helen haslem escort royal duo classroom mother kate miss occasion due acute morning sickness cancel engagements week palace announce monday expect third child like parent george young sister charlotte already appear front cover magazines around world summer travel official royal tour poland germany crowd cheer uk 's prince george start school pregnant mum kate ill go