TextBox over a button? This will look ugly as hell <img src="{SMILIES_PATH}/icon_e_smile.gif" alt=":)" title="Smile">
Or did you mean Text object?
You should add Text and Sprite into the same container. Then when you spawn a new sprite, its text will be created automatically.
Also they will be logically linked to each other. When you pick a sprite instance (for example in On Clicked event), its text will be picked as well.
You can also use the native Button object and style it with CSS:
https://www.scirra.com/tutorials/1283/c ... -textboxes