It is true that US historians discredited the Santa Anna link with Emily, (the Yellow Rose) because no creditable US documents contained first accounts of her being present at the battle of San Jacinto - but Mexican documents do detail first hand witness that Emily was indeed on the battle field with Santa Anna and had been his "guest' for some days - don't be too quick to discount the story.

What is commonly believed to be the original manuscript for this song is in a museum/library in Austin.

I'll go locate more info ...