Thinking that over, Hermione looks down at her hand again, contemplative for a few moments before murmuring, "I suppose I don't really need my left hand. Assuming, of course, that having the shard is a much greater risk than whatever would need to be done to remove it. But I'd much rather keep myself whole and healthy, at least until such a time comes that we have more definitive answers."

While she might be brave, volunteering to be a sacrifice in an experimental procedure when she hadn't even met any qualified surgeons would involve more stupidity than bravery, and Hermione Granger was far from stupid.