"She is the one I mentioned, when we spoke of pruning versus uprooting the tree."

This fire... there are only two of her making in the Dothraki's territory: Drogo's funeral pyre, and the day she'd burnt the hut in Vaes Dothrak. But they are not near the latter; they would have crossed the horselord's gates to draw nearer to the hut, which means, if this is something she should know, then... The timing of their speak about Drogo is well placed.

"You said the Commander slaughtered your twin. Were they both Anubians?"