Catherine has such a passion for Henry (or the "hots" - I'd hope dear Jane would laugh at the phrase), I could see him bending down on one knee at any time between his dancing with her shortly after JT leaves (the same evening Capt. Tilney is introduced to Isabelle) and the present place I am at in the novel! What prevents a Henry from proposing right off? (Ok, Catherine is full young to be getting married yet, and maybe he wants to teach her a bit more, and everything is "promising" but hasn't realized itself yet - confirming Catherine's family acceptability, etc.) But I really do not see obstacles for this courtship!