Why does Hannah feel guilty about getting to open the door for Elijah?

When Elijah's cup is passed, everyone pours a bit of their wine into the goblet. Hannah pours her entire glass, stating that Elijah can have all of it. She doesn't really want anymore anyway. Grandpa Will then commends her unselfishness and tells her that she should open the door for Elijah. Aaron complains, as he wanted to open the door, but Grandpa Will explains that because Hannah's sacrifice was not asked for...... it is much greater.

Hannah, on the other hand, feels like a fraud. Her actions were not sacrificial, she simply didn't want the wine.