[She doesn't, because if this is all she can do, if this is the closest thing to 'help' she can give, she'll give it. How can she not, for him of all people?

Eventually she gets her hand moving--cheats by stroking through his hair, which is soothing to her, at least. Then she forces her voice a little more steady, and finds safer topics to maintain patter--how good he is, and not to worry, and a few tries at how much a help he is, or silly things they should try later...though only a few, since that assumes an awful lot about how helpful she isn't or that he'd spend time with her when he had a choice, and then she has to work on the lump in her throat again which is just wasted time for everyone.

But if he's feeling even just a little less desperate and terrible, then that's all that matters. She tucks him in further into her, while she can]