Heather, when we find her, is surprisingly young and has some odd gaps in her memory. She doesn't seem to know anything about the Grace Group, for example.
Hint 2
There's definitely something odd going on here. In fact, it's so very odd that I don't quite see how you could make the connection except by accident. Read on for a more direct hint.
Hint 3
Remember the roof ghost you met in George's apartment? Learning more about her will help you learn about Heather as well.