Unlike many people in the community from which she's been ostracized, Hannah is a gentle soul, a kind, loving person who doesn't engage in judging other people. Indeed, she herself has been judged, as she has been stigmatized by the local community as a witch.
Among other things, this makes her the ideal confidante for Kit, who is also something of an outcast in a community where she doesn't feel that she truly belongs. Feeling isolated and homesick, Kit needs someone to talk to, someone to whom she can pour out her heart.
Hannah fits the bill perfectly, not just because she's a kind, decent woman, but also because she herself knows just what it's like to be an outcast. As Kit tells Hannah, she doesn't belong in this part of the world. That Hannah doesn't either makes her the ideal confidante.
Over time, Kit develops a very special bond with Hannah, so much so that she's able to tell her things that she's never felt able to divulge to anyone else. Kit tells Hannah about her late grandfather, a man she misses so terribly. Thinking about the happy days she spent in his company only serves to make Kit feel the misery of her present condition all the more acutely.
Thankfully, Hannah is on hand to listen patiently and respectfully to whatever Kit has to tell her. This may not make Kit feel like any less of an outsider, but it certainly makes her life just that little bit easier knowing that there's someone who cares about her.