What a great Day to have a special service dedicated to mothers. Roses or carnations can be handed out during the service. Encourage all your members to bring their mothers. Also check the hospitals in the area and send an invitation to all the new mothers.
God has always encouraged the honoring of motherhood. There are hundredths of scriptures where mothers are mentioned in the scriptures. Unfortunately many Christians have mothers that are unsaved. This is a great way to reach out to them.