Paint, markers, or pens
Do this when you are the most fertile.
Write your wish for a child on the egg, or paint a baby on it. Let the paint dry, then anoint the egg with any oil of your choosing. Rub more of the oil on the woman’s belly, then do the same with the moon water.
Light your green candle, then have both people pray or meditate on having a child. Have sex, making sure both parties orgasm.