] ..Unless Henry’s intentions are real, and known to his sister.

Interesting idea. Eleanor certainly knows that Catherine is interested in her brother. I think she knows Henry well enough to know that he is not uninterested. ;-) I also think that Eleanor is interested in Catherine for her own sake - here is a nice (such a useful word!) sweet, unaffected girl, pleasant company for someone who, I suspect, does not have much female company living in a houseful of men in the country.