Honestly, it depends on the job. Let's say we're talking about an accounting position. One factor that heavily factors into this position is her ability to crunch numbers and understand math properly. The better she understands math, and the more efficiently she uses tools such as spreadsheets and calculators, the more likely she'll get and keep the job. Training would have to be done, either onsite or in some sort of school or at home, to improve these specific skills. This is one way to improve human capital.
Also, despite accounting being a trade that isn't really social (compared to other fields), she still needs to be a decent likeable person to get and keep the job. She needs to impress her potential boss during the interview. One way to do this is to be cordial, honest, and respectful. These traits go a long way and some people forget about them. Once she has secured the position, she can't become mean and nasty or else she may get complaints and lose her job. So if she was a mean person, then going to therapy sessions or having some form of counseling would improve her demeanor which in my mind improves her human capital. Individually she is better off but she also works better with others, which overall helps the company. So this is why it's a good investment even though it seems like it only benefits that individual.
