Black holes don't actually shine, in the sense that they emit visible light, but they are a source of x-ray emissions as well as Hawking radiation, which is detectable. As far as the friend goes, it's hard to come to any firm opinion based on just the information provided but it seems that she might have been offended by pretty much anything you'd have said. Personally I range from being amused to being annoyed when people make such simple-minded pronouncements about established scientific concepts, especially regarding astronomy. So putting myself in your seat for a moment, I think I might have been tempted to take her comment about "God making it that way" and use it to ask how it was made, keeping the tone one of light amusement throughout.
At the age of five, Skagra decided emphatically that God did not exist. This revelation tends to make most people in the universe who have it react in one of two ways - with relief or with despair. Only Skagra responded to it by thinking, 'Wait a second. That means there's a situation vacant.'
