she is from Norway, sorry for mixup.You may want to tell your wife:
With effect from 1 July 2001, a Swedish citizen acquiring a foreign citizenship does not lose Swedish citizenship.
https://www.migrationsverket.se/English/Private-individuals/Becoming-a-Swedish-citizen/What-does-Swedish-citizenship-mean.html
but:
Spain
Allows dual citizenship with some Latin-American countries Argentina, Bolivia, Chile, Colombia, Costa Rica, the Dominican Republic, Ecuador, Guatemala, Honduras, Nicaragua, Paraguay, Peru and Uruguay, Andorra, Portugal, the Philippines and Equatorial Guinea.
Spain & Mexico is crime & poverty infested countries anyway!