That's interesting, since 'her' in this context causes something equivalent to a Parse Error in my brain, but 'their' flows completely naturally for me.
Perhaps that's something you should evaluate about yourself then, because I don't think you'd raise the same ParseError if the profession were "nurse". Unconscious biases don't have to be malicious to exist, and I catch myself thinking the way you describe sometimes before realising "wait, this should be fine though".
It's nothing to do with the fact that it's about software development, I don't think (or at least hope). I just find it jarring to see 'her' used as an 'abstract' gender neutral pronoun. In my mind, 'his' has two semantically distinct definitions, and 'her' has just one - and that's just how the English language works.
Agree to disagree on this being a universal 'abstract' gender neutral pronoun problem, and not being profession related.