Yeh Law is 'neither encouraged nor discouraged' and 'provides no advantage' so i think law schools ideally dont want to see it but if you get a good grade in it (that is what is most important) AND combine it with other, traditional, respected subjects, then its fine.
Spanish is good, many lawyers have a-levels in foreign languages.
Law is an essay writing degree so an essay subject (maybe 2) would be useful (English Lit, History, Philosophy, Politics).
A contrasting subject would show you have skills in many different areas which is useful since a law degree does require many different skills. So maths/science or even economics would show that you can think logically and solve problems by applying theories.
So Maths, Spanish, History, Law would be very good, but you can pick whatever you want so just do what you're most likely to enjoy and get the important A grades in