We admit it. This is a hard sell. How on earth is the tinker a guide or mentor for Elisa? He's not an authority figure, and he's certainly not educated.
Hmm. Maybe it's not that big of a stretch. While of course they don't have a traditional mentor/mentee relationship, the tinker nevertheless helps Elisa to grow in strange and surprising ways. She attempts to express herself to him, and even shares her beloved chrysanthemums with him. Perhaps without meaning to, the tinker manages to help Elisa share some of herself – maybe more than she's ever shared before.