Hello Andrena,
I have come across cases in the past where Timeshare property has been in peoples own personal names, so when there is a death it is Spanish Inheritance Tax that would have to be paid by the Beneficiary as per the Will.
However I have also been aware that in Timeshare or Fractional Ownership of Spanish property there may have been a corporate structure set-up, like a UK Limited Company, so that on death the shares in the Company pass to the Beneficiary outside of Spain so no Spanish inheritance Tax to pay.
With the Timeshare or Fractional ownership property being in a UK Company structure meant the other owners of the Timeshare or Fraction did not have problems with Spain Tax office whilst Probate takes place.