My financee has is slovakian and has got residency in Majorca. If we get married is it easy for her to change her name on the residency?

thanks

Has she got the old Residencia Card? If so, I would imagine that you now have to apply for a new registration certificate in her new name. You would have to produce the old card for it to be cancelled.

If she has the new certificate already then you just get a new EX-16 form and tick the "modificacion" box.