Wedding Party Is Wearing Tea-length Dresses Can Mother Of Bride Wear A Long Dress

I have a question from my friend. Her daughter is getting married, and so far the rest of the wedding party is wearing tea length dresses. The mother of the groom is also wearing a tea length dress. The bride is wearing a floor length gown. Would it be rude, or out of place, for the mother of the bride to also wear a long dress even though the rest of the party is wearing tea length?