sancay, you will need the new card that replaced the old E111 form for reciprocal healthcare in Spain. When you find a local surgery you can register there but take the card. You may need to be
empadronado to join but I'm not 100% sure about that.
Some friends of ours are registered with the local surgery and they struggle a bit as they don't speak any Spanish and the people in the surgery don't speak any English. This has to be one of the worst scenarios with regards to healthcare abroad...the language barrier.
It depends where you are going but you can either ask some friends in the area or at the the town hall with regards to your nearest surgery.
I can't see your daughter having any problems. Many small towns have an "ambulatorio" where you can go to see someone in an emergency and they are usually open 24 hours. Probably best to find out where they are beforehand. There is also usually a duty chemist open 24 hours should you just need some off the shelf medicines.
If you are moving to the Costa del Sol I would recommend you join the
Helicopteros Sanitarios which is an excellent and cheap service. They are a mobile GP service that you can call out any time of day and use them as many times as you want.
Hope that helps...a bit!
Justin