Hi Hwagoner,
Good to hear you're enjoying the place, certainly Spain has masses to offer.
If I were you I would enrol your daughters in a local dance school teaching the core subjects of ballet, modern and tap. These are a good foundation for any form of dance and indeed generally - they help learn balance, coordination and team work and of course are healthy exercise. From this they can graduate to better things, but it'll give you an early indication if this is likely.
I don't know Almunecar at all - there may be a Flamenco school there and possibly it's worth a try. But if your daughters are serious about dance they are likely to benefit from some good foundational training and find it easier to learn Flamenco after a couple of years.
There are English and Spanish run dance schools all over Spain and I would recommend that you look for one whose principals are qualified - an example would be IDTA (International Dance Teachers' Association). There are others - RAD & ISTD, but I believe that IDTA are the most widespread in Spain. If they work to a syllabus and take exams this invariably indicates that the teachers are qualified.
Good luck.