When I worked in a hospital environment, the patients would be very upset if their nurses (aids, etc, ) spoke anything but english, they didn't dare what color, size, or sex their nurse was, butthey had to speak english. or there would be complaints. I agree, if you speak in another language, it's rude and makes peolpe thein that you're talikng about them.
Before peolpe get upset, I should mention, I speak 2 languages other than english. Why? Because, when I was little, if our relatives wanted to talk about what a pain one of us was, they'd speak in our grandparents native tongue. I learned both languages, and could run back to my cousins and say'"well you should hear what they said about you."
Seriously, when I worked for a major HMO, they gave report in tagalog,(sic) there were that many philipino nurses.
If the aid question had been speaking to a pt. that only spoke spanish, rehire her, but if not, bye-bye. I wish more employers had the sense to do it. Did she have a history of this, or was this her first strike?