I'll remind you that you took an unbreakable Vow to keep from hurting Harry Marvolo, didn't you? If you persuade Hermione to disappear now or assist in her getaway, wouldn't that mean a world of trouble for the Marvolo kid? Would your Vow rebound upon YOU if he then gets in further trouble for that?

It's a long causal chain of events I'll admit, my friend. But I'm not in favour of anything that results in you dropping dead.