The 1886 "Angel of Help" window was donated by Frederick Lothrop Ames in memory of his only sister who died suddenly at age 46, Helen Angier Ames (1836-1882). Helen is the one Eastoners have to thank for their incredible public library. Painter, muralist (Trinity Church), and stained glass artist John La Farge used his pioneering technique of layering glass, creating an opalescent background of fused broken glass jewels which dramatically bend light (he patented his invention of opalescent glass in 1880). Above you can see Helen's jeweled sarcophagus being carried to heaven by angels. Below, the magenta Angel of Help is emptying her pitcher into vessels of "Need" and "Sorrow" (written in pink above woman's heads). This window is considered by many to be La Farge's masterpiece (another picture of this window can be seen at the top of La Farge's wikipedia page, linked above).
The photographs are from the Unity Church website.