"Thank you, Master Haine," said Toria with a little curtsey. "I thought it best to remind them that the young lady giving them coin and bread is half-Stark. If nothing else, so that they understand that it's quite rude to take a gift and then insult the kin of the person giving the gift."
There was no need to use force for this reminder. The woman was guilty of rude speculation, not anything blatantly treasonous. Had she wished death upon the Starks, that would have called for something considerably more forceful than a mild verbal reprimand.
"Of course, they may simply attribute my generosity to being a Lannister and say that I am far more Lannister than Stark...but if this calms them somewhat, I will be glad."