Grosvenor begins to explain with polished expertise to Willow what she is, and the rules she needs to know up front. Oh sure, it's laced with nockerisms, but it's actually an efficient sum up in a relatively short time. Willow seems to defer to Sparrow (As well she might) , but whether that indicates she served in a court in past life or just has instinctive respect for the monarchy ? too soon to tell. Once Willow is sure her sister will be safe, and she IS grateful to Sparrow for assuring that, she will follow them towards Earth Runes.