Hi Nancy,
I don't think there's any connection as my grandmother, Luisa de Franca Mendes was born in 1859. She married my grandfather Joaquin Nunes, who was born in Madeira. He had only 1 brother who was also born in Madeira. They came to Guyana and never returned to Madeira. I don't know the name of his brother but I do know that his brother had one son called Ernesto so I don't think there could be a connection.