Guerra was born in Madrid and it seems her interest in painting was sparked at age 12 when someone gave her a box of oil. She is completely self taught and loves the great masters whom she has seen often in the Prado Museum in Madrid, especially Velázquez.
At 23 he entered the Cistercian monastery of Santa Lucia in Zaragoza and from that time has lived her life trying to combine her two vocations: painting and religious life.
Her style is hyper-realistic, her paintings seems to be real photographs and "something that caught my attention when I first knew her paintings is the large domain that she has of the colour and especially the handling of light".
She is a brilliant portraitist and paints mainly young women and children, but also still lifes and landscapes and her characters transmit a spirituality that is evident in their gestures and glances.