Kate and Pippa Middleton are working on their relationship

Kate Middleton has finally ended her rift with younger sister Pippa - but only if she agrees to follow a series of rules.

The siblings had a heart-to-heart two weeks ago after Princes William and Harry convinced the Duchess of Cambridge, 30, to mend bridges.

Pippa, 28, who caused the problem after hitting the headlines with her partying, has now promised to curb her raucous nights out.

And she's agreed to undergo coaching from Buckingham Palace on how she should behave during her forthcoming US tour to promote her party-planning book Celebrate.

Pippa's also agreed to let the Palace 'advise' on her future boyfriends if her recent reunion with Alex Loudon, 31, doesn't work out.

'She's back in the Royal fold after reaching a pact with her sister,' a source tells Now. 'She's acknowledged she put Kate in a difficult position and has agreed to abide by some rules.'

Read the full story on sisters Kate and Pippa Middleton in Now magazine dated 23 July 2012 - out now!

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