In "Tell Me a Riddle" why can't Eva bear to touch her baby grandson after holding him once?

Eva has kept herself isolated, she doesn't touch her grandson because she doesn't want connections..... of any kind. She isn't being cruel...... she sees herself as different. She isn't social, but she's never learned to be social. Her caretakers in Russia took care of her physically, not emotionally. She wasn't allowed to enjoy (Tolstoy, for example), and she says that as far as attachments it's “easy to keep your head above water” if it’sempty as “empty things float”(97).

So, not being able to touch her grandson is an emotional problem, it's scars from childhood, and "love" she doesn't know how to deal with because she never experineced it as a child.