Firing someone in the business world is easy once you get past the emotional part. You already know what you have and it's not working so you do what you must.
However hiring someone is one of the most difficult duties a manager faces. It's not always about who has the best resume. It's mostly about who is the best fit. Familiarity is a huge advantage when you are looking for someone to hire.
Heather is doing what most companies do all the time. She is obviously comfortable with their work ethic, their intelligence their background and their loyalty. Anything else can be taught.
In the immortal words of Gordon Gekko; "Give me someone who is poor, hungary, smart, and no feelings. And if you want a friend, get a did."