Here are some easy steps to follow to check your daughters correct size for communion shoes.
Get two blank sheets of A4 paper, sticky tape, pen and ruler. Place the sheet of paper on the floor flush with a wall and secure with the tape.
Place a foot on the piece of paper with the heel touching the wall. Mark with a pencil the longest point of the foot.
Repeat this process with the second foot.
Measure the length from the edge of the paper to the marked point preferably in cms and this will give you the measurement.
You can now cross check this with the size chart and choose the correct size communion shoe. P.S. Not all brands have the same measurements in communion shoes so you will need to cross check your measurements against the brand you are buying.