The 18-year-old reality TV star wants to treat the One Direction hunk - who turns 20 on Saturday (01.02.14) - to a birthday surprise and is planning to whisk him away shortly after he celebrates his special day.
A source said: ''Kendall's dad has a beautiful cliff-top holiday home in Big Sur, California, and she has asked if she and Harry can use the mansion for a private break together.
''She wants them to have some time alone where they can relax and enjoy each other's company. Harry already has everything he wants, so she decided to organise something special they can always remember.''
As well as treating Harry to a holiday, Kendall - who has been dating the 'Little Things' singer for around two months - is also helping his close friend Nick Grimshaw organise a birthday party in London.
The source added to the Daily Star newspaper: ''Kendall is in charge of organising the party, alongside Radio 1 DJ Nick Grimshaw.
''She wanted the party to be in London so that Harry's friends and family could all be there.
''The rest of One Direction and a whole host of other celebs will be on the guest list.
''It won't be a tame affair, and Kendall will pull out all the stops to make sure it's a night to remember.''