A ceramist who initially ventured into painting, Cristina studied visual education at the University of Guadalajara (Mexico, 1951) and, between 1954 and 1957, low-temperature ceramics technique at the School of Plastic and Applied Arts with Miguel Arroyo. In 1957 she won the National Prize for Applied Arts at the XVIII Official Hall with a set of ceramics. She later became familiar with stonework while working with Francesc Albors and Josep Llorens Artigas in Barcelona (Spain, 1958-1961).

From that moment on, she dedicated herself to ceramics and alternated her time between Barcelona, ​​Caracas, and Paris. Among her group exhibitions was her participation in editions XVIII, XIX, XXIII, and XXVII of the Official Salon (1957, 1958, 1962, and 1967) and in the "International Exhibition" in Brussels (1958). In 1958 and 1960, she received a scholarship from the Mendoza Foundation. She exhibited in a collective show at the "International Exhibition of Ceramics" in Buenos Aires (1962), "Venezuelan Pottery" (Musem of Contemporary Crafts, New York, 1963), and at the Sala Mares (Barcelona, ​​Spain, 1964).

In 1963, the Venezuelan photographer Fina Gómez asked Merchan to participate in the "Venezuela, from landscape to plastic expression" exhibition presented in Barcelona. She obtained a scholarship from the Fina Gómez Foundation (between 1964 and 1966). Cristina exhibited in "Contemporary Ceramics" (Cantini Museum, Marseille, France, 1965). That same year she exhibited the series "The Bugs, fantastic animals that represent an experimentation towards sculptural ceramics." She also participated as a guest artist in "Artisans of the North" (Museum für Kunst und Gewerbe, Hamburg, Germany, 1968) and in the I, II and III International Biennial of Art Ceramics of Vallauris (France, 1968-1974), where her work was recognised. She took part in "Internationales Kunsthandwerk" (Stuttgart, Germany) and was a guest of honor at the Salon de Arte Actual (Museum of Decorative Arts, Barcelona, ​​Spain, 1969). In 1980 she exhibited the show "One Hundred Black Pieces" (Daniel Sarver Gallery, Paris) and at the Museum of Decorative Arts (Paris).

Cristina worked using classic utilitarian vessels exploring ovoid shapes and geometry. Her works were famously painted with satin and matte enamels to achieve monochrome tones and were burned at high temperatures. The artist created her workshop in the garage of Fina Gómez's private hotel in Paris, where she settled until she died in 1987.