Whether your little girl is a Disney's "The Little Mermaid" fan or just fascinated with the finned ladies of the sea, a mermaid costume is the right choice for her. Instead of handing over a lot of money for a store-bought costume she only wears a few times, make your own using a skirt and a bikini top. The finished product is a unique costume that takes little time and energy to create.
Attach small seashells to the front of a bikini top using a hot glue gun. You want the shells to cover the entire top. Leave the straps uncovered. The number of shells depends on the size shells you use and the size of the bikini top. Look for shells at your local craft store.
Measure your child's waist and hips with a measuring tape. Measure your child's height from foot to waist. Add 1 inch to each measurement.
Draw a fish tail shape on the back of a piece of sequinned fabric. Use the measurements from the prior step to determine the length and width of the tail. Cut the tail shape out of the fabric. Use the cut-out tail to trace a second tail shape on a second piece of sequinned fabric. Cut that tail out as well.
Place the two tail pieces on top of one another with the right sides facing each other. Use straight pins to attach the sides of the tails together, leaving the top and bottom open. On a sewing machine, sew the sides together using a 1/2-inch seam allowance and remove the straight pins.
Cut a piece of 1/2-inch elastic to match your child's waist measurements minus 3 to 4 inches. Bring the loose ends together. Place a 1-inch piece of scrap fabric behind the loose ends. Use a zigzag stitch on your sewing machine to secure the ends together.
Place the elastic 1/2 an inch below the top edge of the sewn tail. Fold the top edge of the fabric over the elastic and secure it in place with straight pins. Using a zigzag stitch on your sewing machine, sew down the middle of the elastic to secure it to the waist of the tail. Remove the straight pins.
Dress your child in a flesh-toned bodysuit to keep her warm and covered. Put the fish tail and the bikini top over the bodysuit.
For a hair accessory, attach shells to a headband or hair clips using a hot glue gun.
Hot glue guns are incredibly hot and will burn you. Do not touch the metal tip or glue until it dries completely.