If they did tell her, and Frank happened not to arrive, it might unnerve her so as to make her appearance in the evening doubtful.

Richard, the wiseacre, the inexhaustible Richard, was caring for his cottagers and cutting the leaves of new books--his chiefest pleasure--at Greyhope.
They felt it was a matter they ought to be able to decide for themselves, but still it was the last evening of Lali's stay in town, and they did not care to take any risk.

Strange to say, they had come to take pride in their son's wife; for even General and Mrs.Armour, high-minded and of serene social status as they were, seemed not quite insensible to the pleasure of being an axle on which a system of social notoriety revolved.
At the opportune moment Captain Vidall was announced, and, because he and Marion were soon to carry but one name between them, he was called into family consultation.

It is somewhat singular that in this case the women were quite wrong and the men were quite right.

For General Armour and Captain Vidall were for silence until Frank came, if he came that day, or for telling her the following morning, when the function was over.