Child planning - division of care work/finances

Before describing my question, here is some background information: My husband (33, E13, 3000 net) and I (female, 34, A13, still €3800 net after deducting private health insurance) live in rent (small but very modern apartment in a larger city for €1500 warm including electricity, internet, radio). After I and my brother were born, my mother only ever worked a few hours, which is why she is now completely dependent on my father. She would like to separate, but can't because she...