Good luck! Maybe do a short holiday with her or simply take her outside for a full day and see if she improves.

You could also take some pictures of the suspected rooms especially the walls/ceiling and the bathtub/shower area and post them online to reddit.com/r/toxicmoldexposure and they can give you feedback. If you dont want to post online feel free to send to my email but I'm a layman without special training in this.

Also there are dogs who can smell mold, not sure how many of them are in Spain but maybe you are lucky and one is close to you.