That doesn't have anything to do with her having the knowledge and experience to backup what she says? LOL! Yes, that's part of it. If one spent a few hours and read through all her posts/solutions over the last few years, they'd pick up a lot of useful information.
She also has a lot of integrity. If she doesn't know something or hasn't worked in a particular area, she'll immediately acknowledge it. So when she's sure about something, she's sure about something!
Kevin