Here I looked at the top 100 most followed twitter accounts (according to Twitter Counter as of May 2014), and calculated the gender splits of their followers. I've plotted them first in order of number of followers, then by percent female followers.
Twitter doesn't ask whether you're male or female, so what I'm doing here in brief is using first names to probablistically assign genders, while excluding those accounts that don't appear to be attached to a common name or otherwise couldn't be assigned a gender. See this overly-detailed blog post for more info.
Here's the same chart but sorted by the proportion of female followers.