Hi, Ajanna, welcome to Spain.
Mmmm, I doubt very much such a vegan kindergarten exists...Veganism in here is an alien notion, so it´s highly unlikely you´ll find something like this.
However, you should try to speak to the managers of the kindergarten -whether private or state- and let them know about your kid´s special dietary condition, and hopefully, they may adjust to it.
Good luck!