if the poster hobby takes the same course as the comic book hobby, more women will be here soon.
from 1968 to 1990 or so, women were a considerable minority at conventions.
However during the 1990's a population change happened at these shows, in part because while 40 years ago, it was unwise to tell a date you sold comics & movie posters, now they think it is seriously cool - as long as you aren't wearing the same t-shirt you have been for the recent calendar year and you shower occasionally.
Girls today are every bit as freaky as boys have been forever, so when you go to a comic book convention today, while girls/women are still a minority, you see them everywhere. It's heaven, especially as so many are wearing those Red Sonja & Wonder Woman costumes