I think we are lost without words what you are saying about your children speaking Spanish instead of sign language. Are all children hearing or have hearing loss? What kind of preschool are the children attending? Need help to explain to us.
I teach V.P.K and I teach my children Sign Language and other teachers teaches Spanish. I live in South Florida and either one is not required in our curriculum. A lot of families of the the children we teach in our center are migrant workers. Me personally I teach A.S.L to my pre-schoolers due to it is my preference and I get more results.