A Brooklyn immigrant’s $4 million nest egg is off-limits when she needs it most during her final years because of ineffective court-appointed guardians, her family contends. Aleksandra Chodowiec, 93, arrived in the U.S. from her native Wroclaw in western Poland by herself in 1973 at the age of 43. She worked two jobs, in an envelope factory and cleaning Manhattan offices. In just two years, the industrious Chodowiec saved enough dough to purchase what should have been a golden ticket: a five-story rental building with eight apartments and two commercial units in Greenpoint.