One thing that took us by surprise is that here you pay for the actual cost of the medicine, rather than a flat prescription charge. Fairer I guess but prices vary wildly as a result! I would suggest getting your GP in the UK to write down not only the generic name of her prescription, but also other brand names that are pharmaceutically equivalent, so you can shop around and get the best source locally. Pharmacists are highly knowledgeable and supportive here, but I agree with the advice that managing depression probably requires regular medical supervision and input,
Good luck, Spanish lifestyle is definitely good for anxiety and depression, and even if the move itself is stressful it will all turn out to be worth it in the end!
Maya