Marie Curie realized that pitchblende must contain some elements that are much more radioactive than pure uranium.
In 1898 Marie and her husband Pierre isolated an element they called polonium (after Poland).
While conducting research with her husband they worked under difficult conditions and their lab was in poor conditions that earning a living was not possible.
Thanks to Henri Becquerel discovery of radioactivity Marie and Pierre were inspired to conduct research which eventually led them to the isolation of Polonium and Radium.
They later developed methods which allowed separation of Radium in quantities which helped them study Radium therapeutic properties.
Throughout her life she promoted the use of Radium especially during World War I.
In turn when Bronia left and got a job she would support Maria while she went to University.
So Maria worked as a governess until 1891 when she began studying at Sorbonne University in Paris.
Unfortunately at that time women were not allowed to go to University. So in 1885 she made an arrangement with her sister Bronia.
Maria would work as a governess (teaching a wealthy family's children in their own home) and she would support Bronia while she studied at University.