Include the front piece, the back piece, and the straps. Cut out exterior pieces- one back piece, one front piece, four strap pieces and four rainbow facing pieces. Also, trace the top of the front and the back and jordans little kids about midway down the romper- these will be your lining pieces.
Double roll and press under bottom edge of the lining pieces. Sew, finishing edge, and set aside. Add squares of interfacing to the bottom edge of the strap pieces. Place together, right sides facing each other. Double roll and press the leg bottoms. Sew the front and back together along the sides, right sides facing in.
Sew the lining pieces together along the sides, right sides facing in. Slide the lining into the romper, right sides touching. Sandwich the straps between the back piece and the lining back piece. Sew along neckline, armholes, and back top.