It is not anyone who is able to do this, in fact you have to be very well connected to follow in the footsteps of Charles and Diana, so just how has she managed to swing it?
Well Lucy's father is none other than Jasper Carrot. This alone doesn't get you the St. Paul's treatment (even if the Queen was a big fan of his 'Commerical Breakdown' programme!). It is the fact that Lucy's dad's full title is Jasper Carrot OBE.
Lucy and her actor fiance Owain Yeoman will marry in St. Paul's on Saturday 9th of December - you'd think with a surname like that, the Tower of London would have been a more appropriate venue for Mr. Yeoman to marry!