What “remembered reproach” do you think Lena is thinking about in the following passage?

“....Lena wound Chris’s comforter about his neck…and we watched him climb into the wagon and start on his long, cold drive. As we walked together up the windy street, Lena wiped her eyes with the back of her woolen glove. ‘I get awful homesick for them, all the same,’ she murmured, as if she were answering some remembered reproach.” [Book II, Chapter 5]