she died of a heart attack when the comics first started?
from wikipedia:
The Golden Age Batman first appears in Detective Comics #27, May 1939. Batman's origin is first presented in Detective Comics #33 in November 1939, and is later fleshed out in Batman #47, the 1985 four-issue limited series America vs. the Justice Society and 1986's Secret Origins (Vol. 2) #6. As these comics state, Bruce Wayne is born in the 1910s to Dr. Thomas Wayne and his wife Martha, two very wealthy and charitable Gotham City socialites. Bruce is brought up in Wayne Manor and its wealthy splendor and leads a happy and privileged existence until the age of eight, when his parents are killed by a small-time criminal named Joe Chill on their way home from the movie theater. Bruce is subsequently raised at Wayne Manor by his uncle, Philip Wayne (introduced in Batman #208, Jan./Feb. 1969).