What are the relevant ratios you mean here? I found this data[0] on engineering degrees by gender. Here is the percentage of female graduates for each of the ones you mentioned:
14% - Computer Science
13% - Electrical Engineering
22% - Civil Engineering
14% - Aeronautical Engineering
13% - Mechanical Engineering
32% - Chemical Engineering
Other than Chemical, they're all in the same ballpark. My wife studied Chemical Engineering; I'll have to ask her if she had any thoughts about why it's a higher percentage female.
Interestingly, that same chart has two engineering disciplines that tower over the other two: Biomedical, and Environmental, which exactly squares with the hypothesis put forth by this blog post author.
[0] https://www.asee.org/papers-and-publications/publications/co...