“We all agree that there should be more women in country music,” Miranda Lambert proudly announced at the beginning of her encore Saturday night at Madison Square Garden. “And we also all really miss the Dixie Chicks.” Then, with help from opening act Ashley Monroe and backup singer Gwen Sebastian, Lambert led her makeshift trio through a note-perfect version of the Dixie Chicks’ 1999 hit “Cowboy Take Me Away,” paying tribute to the platinum blondes who came before her during one of New York City’s biggest country shows of the year.