Born in the Governorate of Livonia of the Russian Empire, she became part of the diaspora of artists who fled Latvia during World War II, and eventually settled in the United States where she was a successful painter of landscapes, figures, and still life for almost 50 years.

Lucia's father was a Roman Catholic priest in the St. James's Cathedral, Riga, Latvia until the family fled to Sweden during World War II.

"[5] R. Stevens of La Revue Moderne, commenting on a December 1968 installation of her work at the Galerie Roccia in Montreal, wrote, "Lucia's paintings are powerful and heavily textured.

Many of her paintings have been donated to charitable endeavors, such as the Women's Hospital in Cleveland, PBS Channel 13 (New York) and the American Cancer Society.

Influenced by Leonardo da Vinci and Rembrandt, these artists paid particular attention to issues of light, coloring and texture.

With naïve expression, painters preserved their closeness to nature, accenting mythological, historical, and traditional Latvian ethnic motifs and folk art.

Along with Mārtiņš Krūmiņš (1900–1992), Jānis Kalmīte (1907–1996), Aleksandra Belcova (1892–1981) and Vija Celmins (born 1938), Lucia Peka began to be seen as an expressionist painter well-known in the World War II Latvian diaspora community.

[8] Throughout their 50 years of exile from Latvia, these painters kept alive the folk themes of Latvian ethnic culture in the face of invasion and occupation by foreign powers.

[9] Peka and the others attempted to develop an expatriate Latvian national art, following in the footsteps of artists such as Ādams Alksnis, Teodors Ūders,[10] and Vilhelms Purvītis.

When asked about her preference for working with oils and the pallet knife, the artist compared her painting to "cooking with butter, both having a similar texture."

According to Dr. Ansis Karps of the Latvian National Museum of Art, Peka was, "always surrounded by music, and had a wonderfully sensitive and absorbing life as she sought to express feelings, desires and dreams through oil painting."