I think the original commenter's point is that calling grown women "girls" is a commonly used tactic to infantilize women and make the situation seem not as serious as it's supposed to be.

Take for example the headline that we're talking about here: "girl" vs "woman" is the difference in thinking that this is some 16 year old who made dumb decisions and someone who probably understands the consequences of what they're doing and takes proper precautions to prevent it.

This is not to say that I personally believe that one abortion is more justified than the other (because I don't), but just want to point out the semantic difference here.