Wherever you see "Cantando" or "Cantan Juntos" ("singing", "singing together")
At the end:
Niña, niña que riegas la albahaca,
¿cuántas hojitas tiene la mata?
Niña, niña que riegas la albahaca,
¿cuántas hojitas tiene la mata?
More:
Tengo los ojos azules
y el corazoncito igual
que la cresta de la lumbre.
...
Con el vito, vito, vito,
con el vito, vito, va.
Yo no quiero que me miren,
que me pongo colorá.
There's not as much as I remember, but because it's short it may be more appropriate for young kids to learn. As for the tune I'm not sure. If only all the kids spoke spanish you could've acted the play for them!
I did some googling and these seem to be popular (thought I know nothing of spanish nursery rhymes). Google their names for the lyrics:
Al Juego Chirimbolo
Los Pollitos
Los Maderos de San Juan
Un Elefante Se Balanceaba
Cinco Pollitos
Naranja Dulce
Los Animalitos
Tengo, Tengo, Tengo