Helene (Lene) Schneider was born in Vienna, the daughter of the Jewish painter Sigmund Schneider. She began studying art in her home city, then continued her studies in Munich, and from 1909 to 1912 in Paris. It was in Paris that she got to know Ludwig Kainer, who had embarked on a painting career after having first trained as a doctor. They married in 1910. In 1916, Schneider-Kainer exhibited with the Berlin Secessionists and with the association Die Juryfreien. Her breakthrough as an artist came in 1917 with her solo exhibition in the Fritz Gurlitt Gallery. In 1931, she was awarded the Rome Prize of the Prussian Academy of Arts that enabled her to spend several months in the Villa Massimo in that city.
The rise of National Socialism prompted her to move to Mallorca in 1932, then to Ibiza in 1933, where she opened a guest house for emigrant artists called Ca Vostra. It was destroyed in 1937 during the Spanish Civil War. She then emigrated to New York. In 1954 she moved to Bolivia to join her son Peter.