I know Christmas is almost here, and I meant to get this out sooner- but here it is! You can print this off and frame it for a nice display. Your kids will not forget what Feliz Navidad means. For more fun go listen to the song Feliz Navidad!
And for more information on Spanish Christmas songs, check out this website. Apparently, many of the villages had some songs that they enjoyed singing that were upbeat and fun. The church clergy saw this and adapted the songs to teach religious concepts and stories and to, of course celebrate Christmas! These songs are called villancicos. https://madremillennial.com/canciones-de-navidad-para-ninos/
You can search YouTube for examples. Here is one that has the words written underneath and lots of repetition.