Great-Aunt Carolyn goes to meet Jane Austen in the sky by Chapter 2, but without her, our protagonist Jane would never have seen Austenland in person.
Great-Aunt Carolyn had a terrible marriage, and didn't want Jane to repeat her mistakes. She was worried that Jane was on track to do just that, because of her obsession with Pride and Prejudice and the made-up narrative of Darcy and Elizabeth.
Honestly, though, we have no idea what Carolyn's motivations were. She wanted Jane to give up her silly, love-sick dreams, saying "No use leaning on someone else's story all your life" (1.42). But then she goes and sends her to a place where she can live out that story. Did she want Jane to find love? Or get over her obsession? Or both? Do you think Jane's happy ending would have made Great-Aunt Carolyn proud?