This first miracle shows us how powerful Mary is. Jesus would not have done anything about the wine running out if Mary had not told him to. He said that it was too early for Him to do a miracle, but Mary could make Him do it anyway. It is not like the bride and groom had done anything bad, it was just embarrassing for them. How loving Mary to think about helping in small things like that. Mary told the servants to do whatever Jesus told them (Jn 2:5). It is the same with us. Mary will not tell Jesus to be merciful, or to do miracles if we do not do as He says.
Mary is the admirable Mother of the Son, Who took pleasure in humbling and concealing her during her life in order to favor her humility, calling her by the name of, “woman” (St. Jn. 2:4) as if she were a stranger, although in His heart He esteemed and loved her above all angels and men. - St. Louis De Montfort