Personalized Mermaid Birthday Shirt Monogrammed 1, 2, 3, 4, 5, 6 birthday shirt is so sweet!! The number is appliqued with a purple sequin sparkle fabric and the mermaid even has a aqua sparkle tail. You can choose any number 1-6 and this is also personalized with your childs first name. This is a regular style tee shirt and you can choose long or short sleeve. Just add the first name and the age in the notes section during checkout.